Haywire
Your husband is being an arse - there is no question about that right now, but as Offred has said (who is not ranting IMO) you cannot change him.
You can want him to change, you can wish for (I suspect) the man you thought he was (been there - it's horribly painful) but that's not going to change him.
So, the iron thing - are you saying that even with the supplements your iron doesn't improve particularly so the Dr. just blindly prescribes more? Because that really would be worrying and would clearly indicate an absorption problem.
If you're not saying that, if the tablets work but 3 months or so down the line you are back on the same merry-go-round then unfortunately it is because you are not getting enough (it's absoliutely possible to eat raw broccoli for breakfast - I used to do it using a decent blender such as a Vitamix)
Do you actually feel any better when you are taking the iron tablets? (assuming that they do work and your blood results show that)? If not (and I suspect not) can you not see that something here in this mess has to give and right now that is YOU?! Don't you think you are more important than that? What will you do when you finally break down completely and end up hospitalised? What will your children do? What will your husband, with his nasty manipulative tactics, do with that information in your medical notes during a potential children's act court battle?
Of course that is all speculating but YOU have to look out for you because no bugger else is going to do it.
You say you cannot afford to stop work. OK - what if that choice was removed from your control? What would you do then? Because you'd have to do something - what would that something look like?
Right now you seem to want to control everything because, possibly, you feel like you have no control but what you're actually doing is setting yourself up to fail because at some point you, being a human being, are going to go bang.