How do I maturely handle this ?

Do you ever just really feel like your relationship is struggling but Your boyfriend thinks everything is fine and dandy and he is just oblivious to everything ? 
We aren't exactly fighting and maybe I am emotional sometimes but he just is only intimate when he wants to be and he acts upset/annoyed when I want to have sex or want to be physically close to him.   
I don't care as much about the intimacy issues as much as just him distancing himself from me but I just don't know what to do. I wouldn't peg myself as clingy but sometimes I just want a kiss or want to hold hands ! 
I just feel my man is distancing himself from me and I don't really know why . It's almost as if he's hiding something , and I know he wouldn't even think of cheating , but what else  could this be ? And how do I talk about it with him without seeming suspicious of him or dramatic and needy ?