I am mentally confused with my girlfriend and need help before things go spiraling out of control!!!!!!?

me and my girlfriend have been dating for over 4 months now and i need help. off and on i feel as if i don't want to be together anymore, but then sometimes i do. i can never make up my mind and my mind changes a lot. i don't know what i want to do because i can never make up my mind and i don't want to regret my decision. i am confused on whether i really like her a lot or not because that also changes, and i don't want to make the wrong decision and regret it. i imagine doing that and it hurts breaking up, but i also would kind of like to. i don't know what to do and would very much appreciate the advice because all of my past relationships have been like this and it's time for a change. i've tried meditation, more sleep, time alone, relaxation techniques and other things but they don't help. please help me before i hurt another person and myself. i feel less confident in myself all of the time.