What have I become??

hey guys.. I’m a 20 year old girl. Ever since I was 14 I started getting into serious relationships with guys and after I’d break things off with them within a few days I’d be with another guy and well you get the point.. I’ve never really been single until now..Recently I went through a bad breakup that hurt me in a way I’ve never been hurt. He was the first guy I ever truly loved and it sent me down a dark path after it ended a few months ago. Normally I’m the type of girl who doesn’t sleep with a man unless I’m their girlfriend. But right after my ex left me a few months ago I quit caring. I became someone I’m not. I started sleeping with my guy friends, even my ex’s best friend.. started sending nudes around like it was nothing.. I don’t sleep with strangers its only guys I’m friends with.. and it never means anything to me and I just feel..nothing. How can sex mean nothing? It’s literally nothing to me anymore and now it’s like all my guy friends expect from me. Like I became this easy slut or something. Why am I doing this? I’m still in love with my ex so how can I be sleeping with other guys if I’m still in love with him? Am I doing this out of anger, hurt? Idk.. I just wish I knew what’s going on with me. Sex used to mean something to me but now it means nothing.. it feels as if kissing is more intimate to me than actual sex. Can someone please give me their input on what could be going on with me? What I should do? Please...