I am still in love with my ex best friend

So I (28f)have known L (28f) since second grade and she actually use to be my biggest bully growing up. She was ruthless and very unkind.
In 8th grade, her, A, and I became the best friend trio. Everyone in school knew who we were and who we ran with.
High school comes around (10th grade) and A has to move to California right before we start.

L and I grow significantly closer and I slowly started to fall in love with her. Like, she was all I could think about. I lowkey fantasized about her and actually being together and I wished she maybe might feel the same.
Junior year rolls around and we have a sleepover. L and I take “cherries” (Dextromethorphan pills)and we decide to invite K over bc he can get us a bottle. After a few round of truth or dare and we all kiss, K gets white girl wasted and throws up all over my room and passes out in my closet. We’re all drunk when L climbs into bed with me and tells me to wake K up because “we’re going to have a threesome”
Immediately I perk up. I get out of bed and try to wake K up and I tell him, “L said to wake you up bc we’re going to have a threesome”. He brought his head up and said okay but then put his head back in his own vomit.
I climb back in bed and tell L he won’t wake up. She then turns to me and says “oh, so it’s just us then”—- and kisses me. I. Saw. Stars. We did everything you can think of and it was amazing. She was the first girl I had sex with - let alone person. We go to bed and K leaves early in the morning and I have to help L get throw up out of her hair. I guess while I was sleeping she fell off the bed and went to sleep in K’s vomit. Romantic, I know.
She’s super hungover and then asks me what happened last night and I panic. I ask her if she remembers anything and she tells me she completely blacked out and doesn’t remember anything. She eventually goes home and in my head I’m freaking out.
We’re best friends and I don’t want to ruin our friendship but I don’t know how to go about telling her what happened while we were drunk but I also think she should know. After HOURS of panic, she texts me “omg did we have sex last night” I send back “yeah lol we 69’d” she sends back “still friends?” And we remained friends. She was one of the most popular girls in school and I was pretty quiet but I told a few people what happened and it got around the ENTIRE school. She also had a boyfriend which is why she was so upset when she found out I leaked that information.
Our friendship was never the same. We stopped being friends for other reasons when we were 19 and have basically kept our distance for almost 10 years.
I have been with my boyfriend, S for 9+ years but to this day I still think about her and miss her. She was the first love I ever had and my best friend. Last time I saw her was last year when our friend, C died. I wish she was still in my life