How do I find happiness outside of my partner?

Recently I just moved an hour away pretty unexpectedly. It’s been really difficult for me because I’ve always lived in the same place my whole life and this is a really huge change. Well I’m 16, going into my junior year of high school and I think the hardest part about moving has been the fact that now I’m farther away from my boyfriend. I know many people look at high school relationships and think of it like a fling, but it doesn’t feel like that at all for me. I’m really truly in love with him and he makes me happier than I’ve ever been. I know he feels the same for me. It’s just that lately, I feel like I can only find true happiness when I’m talking to my boyfriend. I don’t have any close friends right now so he’s basically been the only person I’ve been talking to. I’ve just been very depressed and I’m still struggling to accept all the changes in my life, and I know it’s not healthy nor is it fair to him to rely on him as my only source of happiness. But it feels that way to me. I feel anxious and sad whenever we’re not talking or interacting with each other, and I know I need to find ways to be happy and not lonely without him. I guess I’m just looking for some advice right now, to get past the separation anxiety and to be able to find happiness on my own. If you’ve read this far I thank you and appreciate the time spent :)