You need to lay it all out for him. the raging, the med skipping, the hiding it.
and you need to follow things through yourself, to the most likely conclusion.
you are either going to stay and take it. or you are going to get out.
if you stay and do nothing nothing changes.
think.
you say you can't talk to him. very bad. he rages all weekend? and you want to have a child with someone that behaves this way?
there must be some reason why you married him. so there must be some of that person in there. you need to get through to that part.
Impress on them how important this is. therapy. medication. or

I have been in pain and in a serious suicidal depression for roughly 7 years.
I have a chronic pain problem. it's not going away. and I have been on meds that made performing impossible, and meds that made finishing impossible. and for any man it's bad. for a seriously depressed man it's too much to handle at the same time.
I got different meds. things function just fine. sometimes the meds made it better.
and therapy is hard work. Also no one has to know he's in therapy.
seriously things will turn one way or the other. he will hurt you, or himself.
it can't go unaddressed.