I don't like what I see in the mirror

For awhile, I was pretty comfortable with my body; I didn't really care what I looked like. Now, though, I look at myself and I don't like what I see. I see my muffin top spilling over, my huge thighs, an uneven tan, and some frizzy hair. I don't feel pretty.
My friends would say "Don't say that! You're beautiful just the way you are!". The thing is, if I asked them to switch bodies with me for a day, they'd probably say no.
I was told once that it's my confidence that makes me pretty. What about the days when I'm not confident? What about the days when I'm so insecure and want to curl up in a hole and die? Am I less pretty then?
My point is that beauty is subjective so some people might say I'm alright but other people might think I'm downright ugly. I used to be okay with that. Now? I wouldn't want to switch bodies with me either.
~Wannabe