Absolutely gutted this has happened!
Me and my closest friend went out on a night out last night,the night started brilliantly! Few drinks,dancing the night away.
My friend noticed a old colleague if hers and a few of his friends and pretty much left me to it,at this point I wasn’t that bothered it was 1am and I was ready to go home. I told her I was heading home and do you want to taxi share, she said no going to stay here, I said I didn’t want to leave her there alone with all the men as they starting taunting her one put his lime from his glass down her cleavage. I told her I didn’t feel comfortable leaving her with all of them, she then said il go home with ** !! The colleague! She then said text “husband” tell him Iv gone home with you!
I refused to go along with it and left pretty angry!
She came down the road, staggering all over the place. I was flagging down a taxi. She walked up to me but fell back falling on her bum I picked her up linked her arm and tried to get her in the taxi!
She pulled her arm from me and slapped me hard in the face muttering something. I looked at her told her fine and left myself !
I burst into tears on the way home!
She’s never been aggressive towards me. Iv known her along time. She’s one of my closest friends.
I told my other half and he told me to wash my hands with her. I texted her this morning saying how much she hurt me and that I was worried about her and asked why she hit me.in that situation I would absolutely retaliate in defence but I couldn’t I was too upset and shocked. She replied saying she’s to fucking hungover to deal with this shit. 
AIBU to let this friendship go? I don’t know if I can forgive.