I have many issues with my body, though I guess a lot of women do. The way I feel about it can change momentarily. Too fat here, too skinny here, I'm pretty, I'm ugly....and on and on.
And even though I've been going to the gym for a few years now, and jogging for longer, I still feel anxiety whenever I go: fear of looking silly, of people looking at my body and being disgusted/critical. It helps to take a weight training class (I'm still in college) which means there are only a certain amount of (the same) people around. That gives you a chance to get used to them, which slightly lowers the anxiety. Just have to push through I guess.