should we break up


my boyfriend and i have been together for three years, i’m 20 and he’s 18. this year has been hell for me going to psychiatrist visits and therapy visits. he likes to hang out with his friends and i get super upset when he hangs out with his friend and not me. my therapists things i’m a self centered person like how i want things done my way and how i want him to only be with me. we have a lot of problems. he’s hit me once which was yesterday for playing around by trying to touch his butt. he’s insulted me plenty of times. now that it’s summer and we don’t have school anymore, he promised me we would hang out a lot more but ever since school ended he’s been hanging out with his friend. i do get jealous and upset to the point i cut myself. my friend from work says i should break up with him but i feel like i wouldn’t be alive if we broke up. i was always dependent from someone since i was little and i’m afraid to be alone because i’m afraid of what i might do (btw i have no self control) tomorrow i’m finally going on medication to try and help myself. but i don’t know if it’s too late to try and fix things or break it off with him.