On the positive side, it sounds like you have a great foundation there. Though, after 20 years, I think it unlikely that he is going to change his romantic behaviors now. Can you accept the way he is and do your best to work with what you have? No, it does not sound likely that he is going to be the romantic spontaneous guy. Thus, what if you agree to be the one that takes responsibility for initiating as long as he agrees to try his best to consider your needs without sacrificing his own? Sometimes a compromise with a chance of success is better than a dream out of reach.
If his testosterone level has always been low, maybe his behavior will end up being quite different if he gets back on the supplements and keeps taking them.
a fine and enviable madness, this delusion that all questions have answers, and nothing is beyond the reach of a strong left arm.
