What to do when you start liking your best friend

Ive been friends with a girl for a while now. The first year of out friendship, I dated a loads of other girls. But I always spent more time with her, rather than other the girls ive dated.

I dont know when it happened but ive started liking her, and the feelings have become stronger. Ive not dated another girl in a while, I just want my best friend. She is pretty, but I think i started liking her becuase she sort of become a GF without benefits.

what I have done
around 6 months ago, I invited her for a drink. I went out very flirty and sexual. We ended up kissing. We have never spoke about the kiss, but I presumed she felt the same. I felt she wanted me, she kept on saying how im the best looking guy I know, and so many guys and girls look at me. (She has seen both guys and girls come and kiss me).
A week later we go for a drink again, this time she is a little cold. Then she says how she invited a guy around and sucked him off . I get upset but i do not show it. I make an excuse and end the night.

what happens next
Since then ive been avoiding her, I like her too much to be her friend. I do feel sad our friendship is over. She has been making constant effort to be in touch, such as text and late night calls. She even once walked around the whole room to sit next to me in a lecture. She has asked a few times what been going on, but she should clearly know I like her, hence why I behave this way. Every time ive been in a room with her, such as lessons. Ive caught her looking at me. Even in the exam hall, ive seen her do this, so have my friends.
Not sure whats going on with her and this other guy, but around a month ago, she has a snapcaht story up with him.
She also called me on the last day of uni. I dont answer.

so what should I do?

You should confront her about it, she's probably worried sick as to what she might have done wrong (girls are like that, I would know XD). Tell her how it hurt you and if there's nothing there then either leave it as it is or get your best friend back. She's probably missing her best friend rn

well she should treat me like a friend and not kiss me