I’m in love with my best friend

I’ll try and keep this short basically me and this girl have been friends for like a year. We tried being more than friends for a bit during last winter and early spring but she had js gotten out of a relationship and I was really busy so it wasn’t working and we js stayed friends. After summer break ended we started hanging out a lot more after school and on weekends and I started developing a really big crush on her. Over the summer she was in a relationship that ended badly and she was ranting to me about it and how was basically done with dating for the year because of how badly it ended, but that she thought we should try being more than friends around the end of the current school year. I thought that was fine since we’re both juniors so this year is really important, but I was hoping to tell her how I felt at least, but then she started talking to this guy and then they started dating a few weeks ago. Since I’m one of her closest friends, (probably the closest as of now) she talks to me about everything, including how they’re doing and al that stuff. Just before they started dating I realized it was definitely more than just a crush that I had on her, but it was too late then to tell her, and it got even worse when she drunkenly made out with me at a party about a week before they started dating because he left early and she thought he didn’t like her. So now I’m in love with her, she has a boyfriend who I’m friends with and they look really cute together, and I’m hearing about everything that’s happening between them which is actually making my heart hurt. She’s basically my only friend who I’m actually close with, so I really can’t lose her, but it’s making it really hard to go through classes with them and hanging out with them when I can’t stop how I’m feeling about her. Idk what to do but I js needed to rant somewhere since I can’t tell anyone I know irl about this bc a lot of them already thought me and her were dating or something of the like and saying this would make it even worse