Should I break up

My boyfriend and I had plans for MONTHS to go on a trip. I’ve made all the plans and paid for everything. I told him I would pick him up at 9am and he said okay. 7am rolls around and he tells me that his pot dealer didn’t come and that we are going to have to drive to his cousins (40 mins out of the way) to get pot. I don’t smoke but he is a heavy smoker due to anxiety/depression (he takes meds to). I was ready to go by 8:50 but he didn’t even start his shower until 9:30. Finally he’s done getting ready and we get to his cousins house at 10:40. He promises me we can just stay 10 minutes so not to be rude. We didn’t leave until 11:20, 40 mins later because he was talking so long, making no effort to leave. While we are on the road I told him I’m upset at his lack of respect for my time and plans and he screamed at me making me cry. He said keep crying bitch and called me a piece of shit saying he’s not going on the trip now. He banged on my car making it shift to neutral on the freeway and I thought my car was broken because the gas wasn’t working and I couldn’t figure out what happened. We apologized and asked if we could still go and I said okay since I already purchased everything. He goes into his car too get his things and takes over 10 minutes when he knows we are in a hurry. Should I break up?