Why do I have to finish an to go to sleep?

I keep having ual dreams that wake me up on the brink of an . But I can go back to sleep, and my body stays until I sort of think about what happend in my dream and make my self climax. But then I feel guilty because I am a 30 year old virgin, who is a christian. I feel dirty afterwards, but get rest until I get that satisfaction and release. What is wrong with me and how do I stop doing this. I think sometimes I should get married just to stop this and not feel guilty or like I am comitting a sin.