Op, initially I wasn't sure what to think, reading your post. As more and more info was revealed though, I have to say alarm bells are ringing in my head for you!
Takes deep breath
You sound like me 10 years ago.
I had a DH who gave up work just before I gave birth to DC1, he prefered to spend all day and night playing computer games and smoking drugs rather than working.
When DC was born I had to go back to work because we were flat broke and had no money - DC was 2 months old and I was recovering from a significant injury as a result of an accident but I had no choice. DH refused to go back to work so became a SAHD. Supposedly. He did absolutely nothing at home. I would go and work a full time job and do all the jobs around the house as if he wasn't there. I got used to having a relationship with the back of his head. I used to joke that I could up and take the kids and walk out and he wouldn't even notice. It stopped being funny when I realised it was true.
On pay day I would go to the cashpoint, withdraw all my wages and give him half, if not more. He guilted me into doing so saying it was for the DCs but I know now that in reality hardly any of that money was spent on them it was spent on drugs himself. I had to use the remaining half to pay all the bills, food, electric etc. We got into massive debt because I had to choose which bills to pay because it wouldn't cover everything.
Year after year I made excuses for him, defended him to others saying that at least he didn't cheat or hit me, he wasn't that bad etc etc. And he wasn't. He wasn't evil or malicious just incredibly selfish and lazy and incapable of putting me or the DCs first. Promise after promise was made and broken and the excuses just kept coming.
Fortunately for me (or unfortunately) when I finally woke up and kicked him out he buggered off and left the area and had virtually nothing to do with me or the dcs anymore so I went from being a full time worker to being unemployed overnight as I had no family/friends help and couldn't get childcare for disabled dc. I lost all my friends, my job and consequently my home within 6 months and had no help at all but it was STILL better than what I had been putting up with.
Half assed help is definitely not better than no help, you might think it is but I know from first hand experience it isn't. Your self esteem and self respect take a massive nose dive in addition to being exhausted from doing all the work all the time.
I'm not saying that your DP is like my Ex but please just think very carefully. Don't waste your life.
By the way, YANBU to buy yourself the bag 