boyfriend struggles

I met my boyfriend through a friend at orientation, they are roommates, and had an instant crush. When we went on our first date I ended up staying over with him but all we did was make out. In the morning I felt like things were going too fast as we had only been talking for a week and told him I needed a little space. He wasn't very happy about this and actually ended up having sex with another girl the next night and I found out but he denied it. He bought me flowers to make up for "the rumors people were saying about him."  He later fessed up about it and I wanted nothing to do with him at that point. He continued trying so hard to get me back but was still talking to the sex girl because he didn't want to be a douche one night stander. Long story short I eventually forgave him, he chose me over her and we were good. So my boyfriend and I have been dating for almost 2 months now and I lost my virginity to him but now I am finding things out about him and don't know what to do. He made out with another girl when we were talking only a week before we started dating and I'm just finding out about this now. And for about a month of us dating he was still talking to his ex girlfriend and when I told him he needs to stop he told me he would, only for me to figure out he was still talking to her with a different name in his phone. He's been working to let her go but she really messed him up and caused him to have thoughts of suicide. I need some advice about what to do I love him but he hurts me so much and I can't trust him.