Need advice with ADHD husband. At wits end

I’ve been married to my husband nearly 6 years.  He has ADHD and I’m really at my wit’s end.  We have 2 children but it feels like I’m raising 3 children.  The worst part is, my eldest has ADHD as well.

I can’t stand it anymore.  He keeps threatening to leave whenever we have an argument.  He really believes it’s over and constantly gives me that “talk”.  Which is his talk about him leaving.  I tell him he’s free to go but he never leaves. 

He keeps getting in trouble with finances and keeps lying about it.  Often blaming me, saying he doesn’t tell me because I get like this.  Of course, who wouldn’t get all pissed off when some collections person is calling and he adamantly insists that he doesn’t owe anything?

We’ve been through marriage counseling and the screwed up thing is, I came out looking like the bad person.  The marriage counselor says he’s trying and I should see that.  How am I suppose to him trying when he's a lazy irresponsible jerk who I can't count on???

Every job he’s been into has ended up in disaster.  He leaves because he ends up fighting with his supervisor.  The last one he shoved his supervisor against the wall because he lost it.

Now he doesn’t have a job.  And we have bills to pay.  I got so deep in debt because he asked me to get a loan from my office to pay off the credit card bills.  My office loan doesn’t charge interest.  But then I find out he racked a huge amount of debt again.  I’m just so furious right now.

Without a job, all these collections are calling again.  And since I did an office loan, I’m in a situation where a chunk of my salary is getting deducted.

I don’t know how to get through this.  He keeps twisting things around, saying it’s my fault, even accusing me of being a hypocrite if I can say I’ve never lied or done any screw ups in my life.

He’s also accusing me of meeting other guys.  Like I can even do that when I am so busy working and taking care of the kids myself.

I’ve already drafted a separation letter but how it’s also so hard to leave when I know that he can’t help himself with his behavior. 

I’m really so tired of this.  I wish I knew what to do.