What do I do if I feel like a complete loser who is probably ruining her boyfriend's life?
Why do you think you are ruining his life?
I guess I am a talentless person and I have nothing to offer to the relationship.
I'm sorry you feel like that about yourself, but you shouldn't be so negative about your qualities. Have faith in yourself. Your boyfriend chose you for a reason.
I don't know, I just feel...lacking.
It's fair to feel like you're lacking sometimes, but just know that every person feels that way from time to time. It's how you get past it and move on that matters. Don't put yourself down and worry about building yourself up.