I know the feeling! I totally understand what you're going through. I was with my boyfriend for around a year and although I really, really fancied him at first, and the first 8months or so were brilliant thing started to get bad for me when he got a new job with quite long hours; meaning that I saw him much less. I just kind of went off him-in THAT way. I still liked his company, cos he is a really lovely boy- a great catch so everybody tells me, but I just didn’t feel sexually attracted to him, and it made me so confused cos things had been so good. I became more distant from him, and hugged/kissed him less etc (we'd never had sex) until he confronted me about the way I was becoming more distant from him and we decided to take a break from each other.
That was a few months ago, and now we're just friends (Although he wants more, he’s told me he loves me. I’m not sure if being friends is fair on him, but I do still enjoy is company and wouldn’t wanna just stop seeing him, because we were so clsoe and still get on well). I think I made the right decision in leaving him (after our break we were together for a trial period of about 1/2months until I ended it), even though I must admit I do get jealous if he mentions any females (I think this is just a case of me not wanting him, but not wanting anyone else to want him either! I’m difficult like that!).
It makes me sad that my relationship with him kinda died away, but I am much happier out of it-I used to make excuses for not staying round his, and it was making both of us upset (he wasn’t getting enough affection, I felt guilty for not being affectionate). I think I’ve rambled on a bit here, and not really sure I’ve come to much of a conclusion for you....basically try it for a bit longer, I was with my boyfriend for a few months after realising I no longer felt the buzz of excitement when I was around him, and I think it was necessary to have that time to help make up my mind about leaving him. He was very good to me, and I can see why people see why people think he’s so perfect but things just weren’t right.
I guess you've just got to decide whether life without him would be worse than your current situation really. Relationships are bloody difficult things, I just hope they start to get easier as I get older! Though when I think of getting older, I then worry that I might not find the right person to settle down with, which worries me because I want loads of children! Though that's for another post. Sorry for rambling(and excessive use of brackets!), and hope my post has been of some use!xxxx