In a normal situation, it might be sweet and noble to help out your SO. The thing is this is not a normal situation and I can say pretty confidently that your love and anything that you go out of your way to do for him is tainted by the abuse and causes you to "try harder" to help him and go out of your way for him, etc. Thing is that this is the nature of abuse. The tendency a lot of times is for the victim to feel a strong need to fix, help and care for the abuser, many times even feeling like the abuser is the one in need. In other words I think it's typical for the abused SO to almost feel as if the abuser is the one hurting! I know this may sound backward, and it is but it's true. It's clear in your latest statement saying "if he could only learn to express himself..."

My thought is, let him learn to express himself first without you there. The true test of how much he loves you is getting out of the situation and forcing him to look at himself. You won't get him to change a dang thing while you're basically staying, in essence telling him his behavior isn't bad enough to change. Honestly. If he truly loves you, he'll get the help he needs at that point and when and if he's changed his behavior and proven himself to you, you can take him back, go back with him etc. Unfortunately, a lot of abusive men just move onto the next victim.

It comes down to your safety. The longer you're there, the more he learns his abuse of you is ok, and therefore, most likely will escalate. In time, it will get worse, if you stay. I can almost guarantee that. Until such point he harms you badly enough that you end up in the hospital or worse.

You say you can't leave. You can. His life won't end because you leave, neither will yours. In fact if you leave you can start a real life and find someone that will treat you with respect and dignity.