I don't know what it is, it's just the past few months or so everything he does pisses me off. When we're kissing I feel like I can't breathe, I just want to pull away but his face is right in my face (obv!) and it's so claustrophobic. When we're in bed if I'm sleeping facing away from him he'll try and stick his penis in me constantly repeating stuff like "is that on target?" or "is it in?" 
Its so annoying. During sex he puts his mouth over my mouth but doesn't kiss me, just stays like that and I just can't help but pull my face away, it's claustrophobic and tbf plain wierd to just open your mouth over someone elses but not actually kiss them.
I suppose he's always done this stuff and I never used to mind so why is it bothering me so much now? I just find myself making excuses not to have to sleep with him (too tired, stomach ache, headache etc).
It's not just that though, it's his wierd behaviour in general that is starting to annoy me. Like we were over-charged in asda for some pepsi and he checked his receipt, decided to go back and check the shelf whilst I waited for him near the tills and when satisfied that we had been over charged he came walking back really fast (not a normal walk iyswim?) with a really strange expression on his face, practically ran to the customer services and had a bender with them over it. His behaviour was NOT NORMAL although I can't quite put my finger on why iyswim? I just found myself looking at him thinking "you really are quite strange".
I care for him and like I said, none of this stuff bothered me before but now it's every little thing he does pisses me off and embarrasses me. My life has changed dramatically over the past year. I have gone from being a sahm nobody with no friends or future prospects to being a full time student, going to uni in september and having a big group of good friends and regular socialising.
He hasn't changed. I have. Is this why this stuff is starting to become a problem?? I'm also starting to suspect he could have aspergers. He randomly changes to topic when I'm speaking. Outright ignores me sometimes but swears he doesn't mean to, for instant we were driving through a village the other day and I asked him if we'd been there before as I seemed to remember a train station, he said "no I don't think so" I then went on to say it reminded me of a place I stayed in as a child when my dad was in the army, DP then shouts "ooo look, mcdonalds! I'm starving!" I repeated the thing about the army base (as I hate being ignored) and DP replies "it probably was, I think there is a train station here" ??? wtf??? that was the previous topic!!! He says inapropriate things and sometimes doesn't seem to realise anyone else exists but him. Example is we're on a busy road, DP spots something of interest and slows the car right down whilst he points it out to me. People behind us bib etc and DP doesn't seem to notice.
He would be gutted if I called it off with him and I feel really guilty because he isn't BAD to me, I just don't really enjoy being around him at the moment. 