Re absence making the heart grow fonder: My bf never expresses sexual desire in person, on the phone, or anything. When we first started dating he sent me some very erotic emails, but those were usually late at night when he was drunk.
This seems contradictory to my impression of your bf and his more recent behavior. I am wondering if he really does have some sort of sexual longings buried deep within him, and the alcohol allowed those feelings to come out, therefore the emails. If people are less inhibited when drunk, no other explanation makes sense to me. Why would he choose a sexually related type of activity when he was drunk, rather than some other subject. It makes me think than he can think about sex, but is scared to do so unless drinking.
This might also make sense if he is feeling a little under the microscope with you. Not to say you are doing anything wrong in setting boundaries, etc., but in then end, his life is different when he is with you than if he were alone. Without you he might still be drinking, but also not having to listen to a woman tell him how he should live, get in touch with his emotions, etc. Don’t get me wrong, I don’t mean this to sound as harsh as it does, but in some ways it is a no-win situation for you, or for any other woman in your shoes, or at least he might be trying to make it a no-win situation.
Could it be that the very fact he is held to even a minimal level of accountability (out of fear of losing you) that he then feels the control/pressure/intimidation that he felt as a kid under his mother? It just does not make sense otherwise why he is capable of sending erotic emails. Should you two split, is there any chance he would do so again if he met another woman and he was drinking again?
Are you really SURE his ED is physical and not self imposed? I sometimes get the feeling he is ED because he wants to be and resents you calling him out on it. Think about it… For him to get an erection would mean the comfort of his world as he knows it would completely vanish. He would have to step into a new and completely frightening world of emotions, vulnerable without the protection of his ED defensive wall.