nina, at least when they are older you can honestly say to your kids that you tried your hardest. you are not being selfish though, we all need ''me time''. my ex has plenty of this by dumping my son on her mother rather than let me have him.
as others have siad on other threads, a father can take a mother to court for contact but no court can force a father to have contact (and vice versa in one particular case I have helped with!!)
I would suggest your exh has been the fun parent far too much and never taken responsibility? I know childcare can be a ''drudge'' but if you were able to share this between you, it is not such a drudge anymore and I would hope that he would realise that in can be rewarding to cook dinner, wash up, wash clothes, bath etc the kids as well as taking them out to fun places etc.
I can only suggest that his help from you is scaled back gradually then perhaps? get him to do extra without him realising? I did this with my ex. the only thing she did was breast feed my son and that wasn't much as she was not producing much milk and the whole b'f thing lasted less than 3 months. after he went onto the bottle, she did virtually nothing. after several months of doing everything I was at a point where I was becoming very ill as it was not only my son, but our business and again, all the driving back and forth to the business. I had to do something so I gradually got her to do things. my son did suffer a bit, he was left to scream/cry for longer than usual so she had to go hold him to stop him, that sort of thing. it was easier I expect as we were together, but maybe you can have a think if there is anything like that you can do?
maybe suggest something you know will be closed and then disappear so he can't come straight back and dump the kids forcing him to think therefore?
would you have an ally in his mother/parents perhaps?
friends?
not sure about other suggestions as my head is a bit fuzzy after my ex's latest ''wheeze'' today and the long drive. I did the journey in 2.5 hours going and just a bit quicker coming back today which was very strange as it usually takes around 3 - 3.5 hours each way, but I would not miss it all for the world as his little face beams when I meet him at his school and if I only got to see that face then have to come home without him, it would have been worth the journey.
I'll have a think over the next couple of days, I'm taking my son camping so will be back online on sunday evening if I come up with anything of use