Cheating or Losing interest in me?

Ok me and my boyfriend have been together for a year and five months and we have had our ups and downs such as him cheating on me only kissing a girl or maybe it was a few and I found that out from his old roomate then he asked one of my friends if she would date him if he was single and the only reason I know about this is because she told me and then there was another time when we were at the fair and he flirted with a girl right in front of me and somehow they got eachothers numbers and kept talking and what not and I asked him over and over again to stop talking to her because it hurt because they were getting closer and he kept saying no till one day I thru a big enough fit and told him I was going to leave him if he didnt stop and so he did…then from there things were okay for awhile then he left me we werent together for a few weeks but still talked so then he came back and we have been together ever sense with fighting here and there but thats about it but now he is living with one of his friends and his parents and his friend is a complete and utter nerd and I cant stand him. But anyway here lately he has been staying away and I’ve had this gut feeling that he has fallen for someone else or is interested in someone else and he has a lot of girls on his myspace but im not aloud to be friends with guys or talk to guys unless I get the okay and I’ve told him how I feel about all the girls and he says no I only want you blah blah but like I said lately I have had the feeling he wants someone else and I’ve tried to talk to him about it but he gets mad and irritated and such. And the fact that he has been away and takes forever to answer his phone when I text him but he claims he is always at the place he is staying at. And then he turns the whole thing around on me asking me if im hiding something and doing something and what not when I have never done anything to him thru out our relationship as far as cheating and such. But what do you guys think is he cheating or losing interest in me? he still calls me baby and tells me he loves me and such but I just dont understand why he doesnt want to be around me or anything