It has been six years. How long do I have to bend over and take it.?

I've been divorced six years and he is still trying to control my life! I wrote in court(almost seven years ago) that I would change time sharing with the kids if his work schedule changed. He's changing it EVERY six to three months. He swears to the lawyers that it is part of his job to continually change his schedule. It isn't, I talked to someone he once worked with and the schedule changes are optional (that person just moved to Scotland). I've had to change MY work and school schedule to accommodate him. I got the kids a lawyer and he quit changing his schedule (for a month now) however this lawyer feels I should still be accommodating him. What the hell! I understand people have unforeseen cirstances but every few months he wants to start planning for his time with the kid (I'm supposed to be grateful for notice). How he has it now is he changed his work schedule so gets the kids every day off he has and I never have them on a day off. It is affecting my schooling. I'm just so sick of this every other month he will tell the lawyer something awful about me. Last month he said I was neglecting the children. Well the lawyer and CYFD investigated and guess what the kids are healthy happy and doing well in school. They checked my clean home and my stocked refrigerator (I had no notice of when they would come) . I get they have to investigate and I'm glad they do. I'm not blaming them but what is he going to hit me with next. I don't drink (personal choice, I hate the taste) and he said I was on drugs! I had to go take a pee test. It was negative. I've have to take three pee tests each time negative. Every other month something is new. I'm getting really stressed and school is hard. I'm losing sleep to study. What can I do?