What should I do? I cheated now I can't let the other guy go & always think about leaving?

I have been with my boyfriend for two, almost three years. I love him very much & our relationship has been good overall. I cheated on him about 6 months ago. . .actually it occurred from March til April when I was away doing my internship. We have a usually long distance relationship (in-state) but being out of state put an additional strain on our relationship. I was trying to stay busy, going out exploring the new city, going to the club with my girls--being faithful--then we started having a lot of arguements about my going out all the time, drinking, etc. I felt like he was being too needy & I was suffocating. I was often crouched down in the corner of a club on the phone trying to reure him or in the bathroom on the phone with him while my friends had a good time. I cried in public more than I ever have because of the arguements we were having. He felt neglected & failed to realize that I was miserable being away from home but trying to cover with lots of activity.He said that he felt we weren't on the same page & wanted different things. He said that he would come visit but then his sister needed to borrow some money for a cruise that she'd already made a deposit on (knowing that she couldn't afford the total cost)! One night I got totally smashed and this cute bouncer noticed me wobbling to the bathroom and offered to escort me. He was attractive & charming. He asked me for my number & I gave it to him. He called me later that morning to make sure that I was okay. I had decided not to pursue anything even though he was persistent & always texting me sweet, thoughful messages. It was nice to have someone interested in me not only worried about himself. Living among & working among all women, it was nice to have a male friend, too. One night about a month after we met we had a late night dinner. After the dinner he called & left a voicemail letting me know that he'd made it home safely (as I requested). A crazy ex who had been hacking into my voicemail heard the message & forwarded it to my boyfriend who called immediately. Initially I tried to lie but broke down & told the truth. He asked me to stop seeing the guy but I never did until I moved back home in April. I still talk to the guy & sometimes I wonder what if. I am often wondering what if. . ."What if I moved back or to another city?" I want to pursue advanced education & am currently unemployed, my state offers little hope for opportunity. My boyfriend is hesistant about relocating due to his visual impairment & often says he needs to be close to home so that he can help his mom care for his ailing stepdad. I feel like a bad person when I think of leaving. Now to make the situation more difficult his dad just ped away & I'd feel terrible for abandoning him. I need advice, suggestions, & insight! Please help my stomach is in knots about this!