What is going on with my boyfriend?

My boyfriend and I have been on again off again for about 2 years now. He recently just got back from National Guard boot camp and we had a baby on May 12, 2010. At first he was so helpful and talking about our future. He even just bought a house that he wanted me, my other 2 year old son, and our newborn to move in to. We talked about getting married and everything. Then, he had to go away for 2 weeks for some National Guard stuff. The whole time he was away he was texting me that he misses me and can't wait to come home and be with me and start a family. Ever since he got home, we have been bickering and stressing each other out. He is stressed because he gets up at 3am to work until 1pm and then he is dealing with moving and I'm stressed because I work 3p to 10pm and both boys live with me. The other night he said he didn't want to break up but he wants some space because he is stressed and hasn't rested or anything. I told him ok and that night i texted him and asked him if he still loves me and wants to work on our relationship and he said yes. I didn't hear from him all day yesterday (he didn't even call to check on his son) so I texted him and said "if you want to break up just let me know because this is killing me that you aren't talking to me" 20 mins later he just texted me: "Well......" I said, "Well what?" and he didn't reply. I called him 4 times and he didn't answer. This was all around 11p to 1am so I'm praying he was just asleep, but in the back of my mind i couldn't help but wonder if he was with another girl. I need some advice on what to do. He told me he loves me but then he's ignoring me. I haven't heard anything from him today (he hasn't even called about his 8 week old son). Does anyone think he's cheating or am i just being paranoid and he just needs some space? He's 29 and I'm 23 if that helps.