Rachel Platten - Stand By You Lyrics Meaning

The song itself is about a person helping her lover/best friend through depression. It shows that the person truly loves their friend/lover and would literally walk through hell with them because there is such a strong bond between them.

"Hands, put your empty hands in mine." This shows the person trying to lift her friend/lover out of depression.
"Scars, show me all the scars you hide." This means that the person was mentally or physically harming themselves and she wants them to break out of the habit.
"And the heart, sometimes it's unclear why it's beating." This sounds like it's indicating a reference to suicide, and that her friend/lover has suicidal actions or thoughts.
"Love, if your wings are broken, please take mine till yours can open too." This shows that although her friend/lover is breaking down bit by bit, she's willing to give her all so that they can get better.
"I'll be your eyes, till yours can shine, I'll be your arms, I'll be your steady satellite." This means that she's more than supportive to her friend and she'll hold them up no matter what happens between them.
"Well I'll cry with you on hands and knees cause I..." She will also cry with them because she's trying to make them better and hates to see them depressed.

My own personal experience that I have with this song is the fact that I'm moving from one part in California, to another part. And I have this best friend, who stayed with me when I found out I was moving 2 hours away from him. He has tried to take my mind off it by talking about different things on the phone. We even hung out one day. But when we were in school, we wouldn't stop supporting each other (Although we were a bit touchy with each other and other people thought we were dating). When I first came in the beginning of the year, I met other friends and we were running around being idiots. Until I met him. He was looking sad in the corner and I invited him to come hang out with us. He declined, but weeks later, he started warming up to us. Now, in the present, he's my best friend out of all my other friends. We were both literally depressed and felt utterly horrible at one time in the school year, but we kept supporting each other and made it through (though I'm even more depressed because I'm moving). I literally love him, and I don't want to leave him. I feel like we're soulmates, and I don't want to be split apart from him. Every time I hear his name, I can't help myself but start smiling and I got so excited when I went to school, just because I would see him. We both have the same intrests, and I can't deny the fact that although I'm too young to be in love, I think I am in love, cause it feels too good to not be true.