I've looked at this from the same vantage point as your husband, and like him thought I should soldier on alone. I was wrong of course and left getting medical support for far too lone, which simply made everything harder.
My partner supported me, looked after hte offspring, looked after hte house ,and went ot work. A horribly difficult time, particularly as I was not that easy to help. I guess there are three things out of it I think were the most important
The first was the knowledge I was cared for and my partner wold be there. Even though her presence was hard for me to accept at times it made a huge difference. Unfortunately I was not consistent and some days was OK wiht her actions, such as asking how I was going, and other days was angry, resentful and pulled away. Very hard for her.
The second ting is making every effort to get that proper treatment, if the meds have not been revised for a while then hey probably need to be. I'm not suggesting you and or harp on it, just do what you can. If there is anyone else that might persuade him, colleague, parent, friend, then seek their help.
Even though a mess I cared for my partner and when I knew my actions made things harder for her it did hit home.