"I took my love, I took it down"
Let’s compare “the genie in the bottle” conception of love to the Stevie Nicks “Landslide” conception. Whereas previously love was the interaction with another human being that causes someone to be released from the prison of the self, in Stevie's version, love is an object that exists outside the physical body, possibly freely floating in the air. Since it's outside the body, it can be manipulated just as any object can be manipulated. You can take it down, put it back up, drop it, loose it, find it again, etc. Here though she “takes it down” which may suggest that her love loses its sense of being able to move freely. It gets rooted to the ground where it becomes immobile, i.e. committed.
“Climbed a mountain and I turned around”
Mountain climbing requires a lot of work. You get invested in all that work, but what’s the pay off? Not much here. She turns around, meaning, she conceptualizes her intimate relationship as “a journey” and has decided not to continue the journey. That she chose the journey of mountain climbing not only points to the hard arduous work of the climb, but also to the height of the mountain. The peak is often related to drug experiences (getting high, coming down) as well as the experience of realizing something is not going to get any better, "I already peaked". This is a compound metaphor since it invokes Up is Good/Down is Bad as well as Height is Intensity. The further up you go, the better it gets. The peak of the mountain then is the best possible point in terms of feeling good, but it also presents us with the problem of having nowhere else to go but down.
“And I saw my reflection in the snow covered hills”
Here he have yet another musing on "the self" albeit slightly subtler than the one's before. So we can’t directly see the self, we can only see its reflection in other things i.e. mirrors, the eyes of other people, the backs of spoons. The object that reflects the self also contextualizes it as well. The meaning of seeing the self in a pool of water is much different than seeing the self in the rearview mirror of a car. Stevie see’s her reflection “in the snow covered hills”, a detail that may tell us something about “the self” she is trying to convey.
I’m not going to parse the meaning of “snow covered hills” but I imagine after a relationship ends there's period of reflection not just on “the self” but on the relationship as well. Winter is typically associated with death and so the end of the relationship is mapped onto the end of the cycle of seasons. Ok, I guess I am going to parse the meaning of “snow covered hills”. Winter is also the time for inner reflection as one spends more time inside, especially after a breakup, where one might ponder the questions of “What do I mean without the other person I was just with?” and “what do I mean now that I am not continuing the journey I put so much time and energy into?"
Basically, the idea that's presented is that to know "the self" you must perceive it through reflections. The main reflection we have is the reflection of ourselves in other people, especially the one's we decide to be intimate with. This reflection provides us with pertinent information about who we are, but the context of the reflection, that it exists in another person, skews what we see. It gives us inaccurate information. We only realize this once the reflection we've been looking at for so long is taken away and we are left to project the self onto other things such as "snow covered hills".
“Till the landslide brought me down”
What the “landslide” means is rather ambiguous, but it can be thought of as a natural force, such as a hurricane, flood, or strong gust of wind. Emotions are Forces is a well-documented metaphorical concept. A landslide is a specific kind of emotional force, where the active attribute is that it begins with a very small thing, a pebble being kicked down the side of a mountain that eventually builds on itself to the point where it's an out of control devastating force that pulverizes everything in its path. Emotional states can also take on these characteristics. They can start from something very small and build momentum leading to total devastation.
Also of note is where the landslide takes her which is "down". This is another instance of a metaphor simultaneously operating in two coherent conceptualizations, where "down" can both activate "depressed" such as "I've been feeling down lately" as well as "back down to where I initially began." So it works both with the Relationships are Journeys metaphor as well as the conventional Up is Happy/Down is Sad frame.
Oh, mirror in the sky, what is love?
So again we have “reflections of self” being referenced but this time instead of “snow covered hills” we have the reflection in the sky. Lots of reflections going on in this song. She asks the question "what is love" which is understandable since she just climbed an entire mountain thinking that was "love" and was just thrown down the side of it. Now she's on the ground thinking, "Well, what the hell do I do now? The thing I thought was love was not love. I don't want to climb another mountain. That's a lot of work. What's next?"
Can the child within my heart rise above?
The next line gives us a hint, as the heart is conceptualized as a container. What does it contain? A child and some other stuff that the child needs to "rise above". Rising above or being "on top of" is typically associated with "being in control" such as "let's get on top of this problem." The child, which I'm assuming is some symbol for the innocent self, needs to rise above (no longer be controlled by) the other stuff in her heart, i.e. the stuff that isn't so innocent. This again is a fascinating conceptualization of the self, where within the intimate domain of the heart there's seemingly multiple characters (multiple selves) that are vying for control. That she thinks her "heart child" is the path forward is typical of a particular romantic conception of children being pure and innocent before they've been corrupted by the evils of society, a typical artistic sentiment for that time period.
And can I sail through the changing ocean tides
Can I handle the seasons of my life?
So what's the correlation between oceans and season? Change. There's no stable point you can rest. Breakups of course are also periods of change, which is why all sorts of changing natural phenomena are invoked in this song. Basically, "Look at me change! Look at the ocean change! Look at the seasons change! Everything's changing!"
“Well, I've been afraid of changing
'Cause I've built my life around you”
Let’s go back to the beginning where she took her love and “took it down”. Once her love is down on the ground and immobile she then starts building things around her love. Building takes quite a bit of planning and effort and the amount of work she puts in keeps her from leaving. This is actually a cognitive bias called The Sunk Cost Fallacy. The more effort you sink into something that's doomed to fail, the less likely you are to walk away from it. It's especially hard because she has centered all of her building efforts around something that's no longer central to her life, her intimate partner.
So what have we learned here? Oceans, landslides, seasons, snow covered mountains, are all changing unstable phenomena. They require us to do a never-ending amount of work, i.e. adjust to the fluid nature of reality. Our ability to deal with change is variable. We can get caught in a landslide where the change pushes us down and decimates us or we can sail through the change in a manner where we've mastered the ability to navigate an unstable environment in a graceful manner.
Does Stevie have any recommendations for us on how to achieve this graceful dynamic? Yes. Acceptance. At the end of the song she admits that "I'm getting older, too" an acceptance of the ultimate change we have to deal with, time. In accepting our inability to completely control our environment, we can then move more fluidly within it, thus we don't crash into opposing natural forces, landslides, but rather, glide elegantly with the forces and use them as best we can to navigate ourselves to where we want to go, which she offers up in the image of a ship gliding through the ever changing tides of the ocean.