Most Helpful Guy
Why is he "a total jerk" now? Also, while we're at it, how old are you and he? This is important to know for your well-being because you may discover that every guy is "a total jerk" in which case it is pointless to dump your boyfriend, but better to work with him to make him not be a total jerk.
Most Helpful Girl
Just b honest with him and tell him it's not working out...