Hey /adv/. I don't come round here often, but I need some advice.

I'm a high school junior. Back in freshman year, I started talking a girl who I ended up really liking and I thought she liked me in the same way, since we were hanging out constantly. When I finally gathered up the courage to tell her how I feel, she rejected me and told me she was a lesbian. She's one of my best friends now and we talk almost every single day. The problem is -- I've never gotten over her. I still love her and seeing her with her girlfriend is fucking heart breaking, even though I wish that they stay together as long as possible, since she's so happy with her. There was one girl who was interested in me a few months ago and kept sending me unsolicited nudes, and I tried being with her for a while to get over the lesbian, but I just couldn't do it.

How do you get over someone, /adv/?