i'm torn- please help!

 I'm in high school and he graduated from the same school in 2016. We've been together almost a year but it's been a struggle for several months.  He shoots competitively and much too often he puts that for me (match on my 16th bday- didn't even text me happy birthday, promising to go to all of my meets and missing 3+ because of shooting, my best friend died in june and i told him i needed him and just needed 5 min on the phone with me because the funeral had just ended and i was a complete wreck, he said no he was at a match. etc) but no matter what he will never admit it and thus will never change anything.  he has never once laid a hand on me until new years when i was terrible pain from dry socket and had gone to lay down as my mom let him get wasted and i went in the room he was staying in and i just wanted to talk to him and then he hit me. he always invalidates my feelings and can't even remember things like what time my college class gets out on monday's. there's so much more but there's also so many times that are good. i just don't know if it's best to stay with him or let him go