Hello
im sorry I do not have personal experience with BP but after reading some of your experiences it doesn't sound like BP to me at all, it sounds more like immaturity, irresponsibility, and disrespect. And it sounds like you are allowing it by excusing this behavior. You are young and need to find ways to enjoy your youth. Don't let this person string you along because they are irresponsible with your feelings. If he had any respect or responsibility for his actions he would let you go, and it sounds like he has done that a few times. These are moments of clarity about the pain he's caused you. Please listen to him and move on