I was that way a lot, I still am sometimes. But, it is an exercise in futility. One of the worst habits I have is seeing pretty young things and letting the thoughts hit me about how they are so lucky, wondering what their lives are like, envying their bodies and their lives, etc. That'll just depress you. Every second you dwell on the past you steal from your future. Challenge these negative thoughts. Learn to love yourself as you are. You'll never know what you can be if you don't climb the ladder out of that hole of negativity.