I don't think you're doing anything wrong, other than maybe expecting too much from yourself. I've been in similar situation - worked 32 hours a week, was separated, taking classes, have 3 kids (one with ASD and what looked like ODD at the time), bad finances and no help. It was awful. I had to change something, one thing being my course of study. You shouldn't give up your dreams but is there any way to compromise? Like school part time? That was the therapeutic advice I got that was most realistic...that you can't do it all. You need to take care of yourself in even the smallest of ways. I feel for you. You still have more stress than I did but I can still relate.