what do I do?

Ok so me and my bf have been dating for about 3 1/2 months now and he is older than me (by 5 yrs) but anyways aside from the details of him and me I've been feeling like he's being distant and I'm not sure what it is...sometimes he can be very mean and i dont know why other times he's a sweetheart when we first started dating everything was fine we'd talk here and there or hang out go to see movies just enjoy each other's time now that hes working more I barely see him which I understand but he doesn't really talk to me anymore he works first shift so he gets off work around 3 and sometimes I dont hear from him until 8 or 9 at night and that's if I don't text him first and even when I do sometimes he doesn't reply for hours and when he does and I ask what he's doing he always gives me a vague answer or if I question his whereabouts he gets offensive as if I'm not his girlfriend's but he questions me the same and I have no problem he's very controlling which isn't bad it's just it seems as though I have no say so and if I question him about being faithful he gets upset but then he acts very mysterious and secretive. like one day my phone died so i called my mother for a ride home from his phone and he was outside he came all the way in the house to see what I was doing and didn't leave me until i walked away and gave him his phone back I know you guys can't give me the answers i need but some advice will do I'm hoping it's just the fact that were a new couple and not what i think it is because i havent dated in a while for that exact reason and I'm just scared to find out the horrible truth because I really like this guy...no I love him honestly I fell in love with his personality and how he can make me smile but lately Idk what's happening I don't know if it's me or him...