How does one improve self confidence and body image...without a gym?

[Quantum Modulus]

I've been having some self esteem issues lately, and even though my girlfriend tells me that I'm attractive and whatnot, I am never able to convince myself that she's telling me the truth. I've been consoled so many times about various issues, and most of the time it was merely others telling me that which I wanted to hear -- not what was necessarily true. I always think to myself that she likes me for reasons other than my looks, and even though looks aren't everything in a relationship, they are significant to some degree...I always think that she's just telling me what I want to hear. But, asking her for the truth won't get me any further, so I'm just going to bypass the validity part. I've tried so many methods of improving self esteem and body image, and almost all of them involve repetition of my "good qualities", but that seems like a dead end and purely narcissistic. Doesn't make me believe for one moment that I'm any more attractive, physically. Any other methods seem to involve exercise, but I've tried that with no boost in my psychological state. I don't find exercise to be an effective way to improve my self-respect, so I ask the forum...what other methods should I try out?
@ iWumbo: I really hope you're not being serious...
@ mertyce: I don't really understand the last line of your comment, but thanks.