Tell you husband how it is and that he has to help work on getting himself better. Has to either try something on his own or see a doctor. You are not responsible for what he occupies his time with! Don't let him put it on you that you are not helping him. You cannot do an occupation for him. You've given his ideas, tell him to either do self-help for his condition or see a doctor, etc. Use your own example of seeing your doctor to make the point he needs to do the same if only out of fairness. You are not happy, he is not happy; both of you have to do something about that for their "half" at least!

But have a talk and make up a plan that you find reasonable for yourself and let him know what you expect. If he will not, is not interested in doing for himself or to help you, you need to have consequences. As you say, "I want to be in a happy positive marriage and the thought of living in silence for years is torture." You cannot allow yourself to go down with him, to be tortured, if he will not see help.