Advice on not getting easily offended?

I get extremely offended whenever someone mentions ANYTHING about my weight, face, or personality. Apparently I'm gorgeous, as my friends say, and I do have a good personality (I hate fights, bitchiness, etc). I'm not overweight, but I'm not exactly tiny either. Whenever someone says anything about any of those three things, even though they are joking, I get incredibly offended. How can I stop this?