I've done something bad

So I've been talking to this boy like mates since like New Years time and he told me he liked me mid Jan and I liked him back but small problem he has a gf who I'm mates with and so we were talking for a bit and we met up in a group of people where his gf weren't there but basically he tried to kiss me and I doged it. So then he sent me a dick pic and I sent a picture back then the day after I told him to chose between her and me coz I liked him so so much but he chose her. I was so upset. Then we were still kinda talking after and like 3 days later we did nudes again. Then the day after he met up with his gf and stuff and then a video of them kissing went up on someone's sc I was fuming and so we didn't talk anymore. Then like two weeks after that he text me saying not to tell anyone and then he told her and I get how she was mad at me I took it. All of his mates are calling me a slut and dickhead and stuff I dunno what to do it's eating me up inside I don't see the point anymore I have thought about over dosing like 3 times but my best friend managed to stop me but I don't know what to do even my best friends are turning against me I dunno what to do help me please