I really need some advice.

Hi Everyone,
I could really use some advice on something. Before I tell you I just want to say that I know this situation is bad and that I shouldn't have gotten myself into this mess.

Ok well I'm a gay male and I met this guy in college. We became really good friends towards the end of the school year. We would have sleep overs in my dorm room in the same bed like every night for like a week straight. Keep in mind he is completely straight and has a girlfriend for four years now. We didn't do anything sexually just laid in the bed together we barely cuddle sometimes but nothing major or crossing the line. So the next week I got kicked out of housing for stupid financial reasons and I had to leave my dorm room. He told me that I could just sleep in his room with him. So just like the week before we slept in the same bed, but this time was a little different the cuddling got more intense. On that sunday we were laying in bed together and we were bored so we were talking about stupid random things and somehow truth or dare made it's way in the conversation. I told him I never back down from a dare but we both agreed we didn't want to get out of the bed to play. So okay I know this was bad but I dared him to kiss me and he did it. It was a tad awkward afterwards honestly but to break this awkwardness I asked him how was it and he replied different so another awkward silence falls upon us and we do it again this time with a lot of passion into the kiss. We kiss a few more times and finally go to bed. We wake up and we kiss again but this time it was sweet and cute. He had to leave to go to class but before he left for class he hugged and kissed me. We started sending really cute and flirty texts and we had several late night make out sessions in his bed. We never had sex but we did go further and further each time. Sadly the beginning of the next week was really hard because my mother had kicked me out of the house and I had to be off campus soon. So I had no place to live but my friend had offered me a place to stay in his house which was just the nicest thing ever. So he came home with me that weekend and we slept in the same bed and messed around going almost all the way. After that he went back to school while I stayed at his house. For the next week he and I would text each other constantly but it seemed off to me. He texts seems like held back and not their normally cute and flirty self. He came home that weekend and it was so strange between us like every smile was forced and it felt like he didn't want to be alone in a room with me. we slept in the same bed but we didn't kiss or anything we just slept. I thought I did something wrong like maybe I rushed it and went to far with him. But something was wrong and I couldn't tell what was wrong. So his last week off school was done and he was finally home . I would try to be flirty with him and it felt so one sided which really hurt. I finally had to ask him what was wrong and he just said he wasn't in the mood. Which of course I said I was okay with and told him I understood. I just felt so sad and hurt and couldn't stop crying my eyes out. So Last week I brought us doing stuff and he said that he feels bad for his girlfriend which I understand but I didn't understand what changed between us. Like I mean what made you realize this was a bad thing? And I asked him if he wanted to end this and he said I don't now because if I say no I'm going to want to do it again. Which just made me confused and angry. I was becoming really snappy towards him and just stopped talking to him and he asked why I was angry which made me even more angry because i think I have a right to be angry right? So then I tell him why I'm mad and confused and I feel used in a way because I feel like he made me think that there was feelings behind his actions. And you know I got attached and I put my feelings into as well. He told me that after we stopped doing stuff since were weren't together he started feeling like shit because he was hurting his girlfriend. Which I understand and I was fine with us not doing stuff I just didn't know where to put these feelings because I thought he had feelings for me so I was confused how those feelings just go away. Also it didn't help that we still after that conversation sleep in the same bed together and honestly I know this is horrible because he has a girlfriend and I know I should feel bad but i just don't feel bad for her. She is just horrible and He says just awful things about her. Like he calls her like crazy and just says how dumb she is. I had asked him a while back how he feels about her and he says he's probably going to marry her because he's been with her for 4 years and he doesn't like change. Also really big thing I found out which I wasn't supposed to know is he and her were going to have a baby and they got an abortion. Which I think is another reason he's going to stay. Also I just want to make it clear that I don't want a relationship with him but I miss doing stuff with him. And I know I should just move on but I just my life is been such hell these past weeks and he was the one good thing. I just don't know what to do honestly about my feelings, him, his girlfriend, and I guess this void I feel not being in his arms.