I think jealousy is very typical in young people who are insecure because they have not yet accomplished much, and don't understand their value in the world. As you grow and mature, you will probably not allow your insecurity to rule you, you will develop some confidence, and your jealousy should diminish.
In the meantime, you should work towards doing things that scare you, like talking to guys. It gets easier with practice.
Relax... I'll need some information first. Just the basic facts - can you show me where it hurts?