My Boyfriend Is A Young, 23 Year Old Man. He

My boyfriend is a young, 23 year old man. He has been having problems achieving ejaculation. He has drank a lot in the past and often on a regular basis. Even when he hasn't drank very much he has problems achieving ejaculation. It is becoming a bit of a problem. Are there permanent long term affects with alcohol involving it being hard to achieve ejaculation or do you think if he stopped drinking overall the problem would fix itself?