Fingernails are not my Friend

I can't seem to keep my fingernails from looking like an animal attacked them. When I get nervous, I bite them and they just look terrible. I got a gift certificate for a manicure and I never have the chance to use it! Why would I want to when my nails are extremely short? Waste of time, if you ask me. I really need a new technique to stop them from looking terrible. I want them to be long, and display a french manicure. Help!