Boyfriend feels inadequate because he has cums in seconds.

My boyfriend only wants to have sex while he's drunk because he when he's drunk he last very long he could go for an hour. When he's sober he cums instantly. We do alot of foreplay but when he gets in he cums in seconds. I've told him there's things he could do for it but he just gets embarrassed and ashamed. I hate have sex while drunk its not my thing I don't know what I can do to make him more okay with it,?