So. I have been dating this guy for 4 years and 3 months. We have been together since high school and have been through a lot together. We broke up around our 19month mark in high school and were broken up for 5 months. During this time he told me that he had cheated on me with 2 girls. I was so upset. We stayed broken up although I never fell out of love with him. I completely blocked him out of my life and we didn't talk for a very long time. One day he made a new msn account and added me to it. He told me he made a huge mistake and wanted to try things over again with us. I was scared at first but I agreed.
It would figure that when we were getting things back on track he went to uni, it was kind of close to where I live but it was still difficult. Somehow we made it through. In may of that year his mother passed away. This changed him completely. He was a mama's boy and now she was gone. I have seen him change drastically since then. He shut a lot out but kept me around and I tried to help as best as I could.
I now go to the same university (and it was not based on the fact that he went there lol). For the last 3 months we have been extremely happy and I thought that things were going fine. We hung out all the time and I was getting the old butterfiles back when I saw him.
Just 2 nights ago when I went home for the night he went out to the bar. I thought nothing of it. Until I went back to school the next evening and found out from a friend he went home with a girl. I was SO shocked I had no idea what to say because I never ever thought that this would happen again. So I ran over to his house and lost it. I broke up with him and told him where to go and how to get there. I was feeling good about what I did until I was by myself and broke down. I am still in love with him and I know that he in my soulmate. I have never connected with someone like that before.
I really have no idea what to do. My friends have never gone through something like this and don't know what advice to give me.

"Once a cheater, always a cheater."
I know how you feel, that you can't cut him out of your life. But one day you're going to be able to, and you need to be able to hold on to that. Don't trust him again, and certainly don't forgive him. If he earns that trust, then that's OK, but don't pursue a relationship with him. It can only lead to more heartbreak.

You did the right thing. Now for your own peace of mind go get tested tor STD's. If has been sleeping around there is no telling what sort of nasty presents he may have given you.