If you feel strongly that you need to figure this out, you need to explain that to your boyfriend, and either break-up or agree to see other people until you know who you are. Committing to someone before you've fully developed your sense of self is a disservice to you both.
I have to agree. Before making any permanent relationship decisions, make sure you're the person you need to be. You're no good to him or yourself if you're not sure you are with the right person.