Rebound after bad breakup?

Hi guys. Need some support. About a month ago I got out of a 2 yr relationship. There were some really good parts of it, he was my best friend. But he was really mentally abusive.. we fought a lot and there was a lot of manipulation and jealousy from him... anyways, after we ended things, we still saw each other for the next few weeks on and off and ended up hooking up a few times. I knew it wasn't the right thing to do, even though I love him. I didn't want to lead him on when I knew I couldn't remain in such a toxic relationship. so I cut the remainder of it off about 2 weeks ago. It's been so unbelievably hard... like I've been seriously so anxious and depressed I can't eat or sleep. I got really drunk this weekend and ended up sleeping with a guy I know from school. It was fun at the time, but in the morning I felt like shit. I cried all the way home, wishing I could just be with my ex.... it was the first time I've had sex with anyone but my ex in over 2 years.... I feel guilty and lonely now... and I just miss my ex - my best friend. have you guys been in this situation before? Does it ever get any easier?