You're not a bad person at all! I feel that way too sometimes. It's especially hard being happy for someone else when you can't necessarily be happy for yourself right now. I'm a lot less accomplished than my friends, but it's important to remember that you are yourself, not the people around you, and the only one you need to measure up against is yourself. Give it time and go easy on yourself. Jealousy is a natural emotion and like all the others, it'll fade with time.