Hi
Welcome to the forum. I've only just signed-up myself and have no idea what to say either! I felt like I could write and write and write, but am scared of sounding like I'm doing nothing but moan.
I completely understand about how people seem to take an instant dislike to you. I get exactly the same reaction from people. Making friends and meeting people for me is nigh-on impossible. However, it's not because I put on a happy front. I wish that I could, but I can't do it! Similarly, I keep my depression to myself. Even my doctor doesn't really seem to appreciate how bad it gets.
I've recently split up from the first girlfriend I ever really opened up to about it (very difficult circumstances, in part due to illness). That's crushed me beyond all belief and makes me wish like I'd never done it because I'm certain it was a contributing factor. Though we remain great mates, it's not really the same. The element of trusting someone again has gone. All I can say is that it's terrific you have an understanding fiance. You should cherish that :)
Hope that's not too overwhelming a response. As I say, I'm scared about joining a forum too. I guess I'm trying to be as supportive as I can and say I understand how you feel. Internet anonymity is great! If this were in person, I'd probably be hiding in the corner!