Just completely frustrated

Just got my husband diagnosed with ADHD a few months ago.  After several dosage changes on his medicine, I thought things were so great.  I thought we could finally have a "normal" relationship, but I was wrong.  Now he will threaten me that he won't take his pills if I do this or that.  He takes his pills at odd times when he is supposed to take them the same time each day.  This causes him to stay up all night doing whatever he is hyperfocused on at the time.  We have 2 teens and 2 toddler twins and of course this is all affecting them.  On top of it all, just found out I am pregnant - not happy at all.  Everything I have read in the forums sounds just like my husband but I am at a loss of what to do with him.  He thanked me for doing the research that lead him to find out he had ADHD and get him a doctor and the right meds.  Now he says I am the one who is crazy and I am the one who needs pills.  Do I continue to fight for him and my family and get him more help, or should I give up? 

I want a "normal" quiet, drama free life but feel I will never get that.  Our main problem with his ADHD is money.  He can't handle it, can't budget, can't pay a bill.  I have been "trying" to keep up with our bills all these years but he has made it so impossible.  If I don't give him the money he wants, he throws a tantrum, threatens me, throws things etc.  He always has something going on to make "extra money" but it always ends up costing us in the end and coming out of his paycheck.  I work part time so he is the sole provider.  He has lied to me about money, stolen from me, taken my debit/credit cards without telling me, even forged my name on a check.  He has completely ruined our credit, we have never been able to save a dime and even the kids are tired of it.  Oh yeah, I have to make sure the teens hide their money and debit cards from him too. 

His rage when he feels frustrated or when he doesn't get what he wants is completely out of control.  He yells at the top of his lungs so loud it hurts our ears.  He says the most hurtful things to us all, then the next day acts like nothing ever happened or expects us to apologize.  We have been together for 18 years (I don't know how I stayed so long) and I love him, I do feel sorry for him because of the ADHD and the horrible upbringing he had.  I want to fight this and get him the help that he needs but he is so stubborn he doesn't think he has a problem and that the pills work fine. 

I know from reading these forums that I am not alone and that is a great feeling but I just seriously don't know what to do!  Please give me some advice.