Simply PTSD or legitimate issue?

Ok! I'm seeing this guy, and I really like him. Things seem to go well when were around one another, simple easy. But he gets weird and goes quiet when having to leave. This throws me off and frequently I freak out inside and worry I did something and start to remember my ex (ok that's ptsd). Anyways, I tried quitting smoking recently (mind you after having a major episode of a flashback sparked by one of his facebook status which was over nothing!) And went right back to it. He's seemed more distant since then, which is also when school started again. Today I asked him how his day was and he didn't ask me about mine. He hasent texted me like he usually does in two days, he did give me a gift last we hung out mind you. I don't know things just seem up and down and I can't tell if its me, or him or us both. He has had a rough relationship history, as have I. My previous legtitimate relationship had a lot of arguments, where I was deemed "paranoied, clingy, and obsessive". However when I tried stepping back in it I was told "you don't trust me enough, why don't you initiate anything?!". Most of the time seemingly out of nowhere. I do have ptsd, due to bad relationships, which I even had before my legit ex. Also, my recent ex (not legitimate I think) was never around, made empty promises ect. So yes all this worry could be in my head, but I fear the guy I'm seeing now has gotten bored, or thinks I'm a risky person to be with. I don't know how to act normally in a relationship, I just blurt out random stuff from my past then brush it off so could that be causing issues? Or me being up and down? (Aka I'll try and be affectionate and then freeze physically but then sometimes I'll just be affectionate). I really feel confussed and at a loss here. Am I making up these random distances in my head? Or am I creating them because I'm afraid? Or is everything a-ok? Also I want to ask him if this is working or to be my boyfriend but I'm frozen stiff with fear that it'll ruin things, and I want him to know about the paralizing fear but I also don't want him to feel, like that makes me not girlfriend material. So yes please help, I honestly don't know how to have a healthy relationship. (Ps. Me and him have slept together and agreed to be "exclusive". I've known him for two months)