I don't know what to do in order to heal?

So I want to start this off by saying English is not my first language so excuse my poor grammar!
During all my school years since like 4th grade I have been best friends with the most amazing, beautiful and out going girl in the world. not enough words can explain how wonderful she is. I used to think I loved her just as my platonic half nothing more since for a good 3 years I liked this guy (9th- and mid 12th grade) and I thought he was everything I wanted and my first love but apparently I was completely wrong because I just now realized (2 years after I left hs) that the one I have always had the strongest feelings for my indeed my best friend whom I have never thought of more than a friend but the signs are just kicking in now that I keep seeing her less and less bcs of school and work and I feel so empty and lonely (+alone emotionally) even though I have met so many amazing new people throughout these 2 years but superisingly enough none of them compare to her (side note everytime the guy I used to like did me wrong my head would automatically say "she would never" or compare her to him). I used to be jealous of everyone esp the guys she talked to (she had many fligs with guys and she was strictly straight) and I ended up ruining many of her situationships (not my proudest moment and I was a shitty person to do that) and I only thought that was normal as we are best friends, I also was so close to her and would go insane without seeing her for a day, I begged her to go to prom with me for months and for her to ignore her boyfriend (my classmate and close friend) at a time. She used to treat me so right and I loved her the most, I realized it too late bcs I think part of me never wanted to admit that and I just wanted to stick to liking the guy I mentioned before
I don't know what to do in order to heal?
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