You're getting a bit of a rough ride here, OP, without people acknowledging some core realities, like the fact that minimum wage jobs are a poverty trap rather than a way out.
I can see both sides. I've been both the sole earner and the SAHP. Even though he's in a good job with, presumably, a pretty decent salary, the responsibility for being solely responsible for other people's welfare can sometimes be quite a stressful burden. I think it would be unusual if it hadn't at least once crossed his mind, what happens if I get made redundant? What happens if the mortage increases beyond x amount? It can make you resent the other person, who you may think has it easy because they don't have to constantly worry about these things.
From my own SAHP point of view, it is extremely hard to get back into to the workforce after 5+ years out of it, particularly if you didn't have a good, steady job before you left and you haven't stayed in touch with your contacts. Added to that, local jobs where you can rock up at 10am and leave at 2pm are rare. (And if it wasn't local, forget those hours, because at least where I live, there's no way public transport would get me from the school to town within 1hr.) People suggesting lunchtime supervisor shifts have got to be having a laugh. Yes, those jobs are always advertised at the local schools in my area too - they can't fill them because they are minimum wage and are only 1 hour in the middle of every day, meaning it's highly unlikely you'll find another job to fit around them.
So, although he's not unreasonable for wishing you would share the financial burden with him, your DH is very unreasonable for not wishing to help pay for your further education which, one would hope, would lead to better prospects for you. He's also unreasonable to expect you to continue to be a full time carer for your children and manage the household while working. Have you thought in any detail about what you actually want? You mentioned education - is there a skills-based course you want to do that would help you get a job? Would you be happier to get a part time or a full time role? Would you be happy working if your DH paid for a childminder to do some/all school drop off and pick ups or looked after them after school on the days you're working?