Tracy...just wanted to acknowledge your post, I'm a single mum too and it hurts when they say things like that, I get it all the time, wonderful precious daddy and boring old mum...just remember its easy to be a perfect parent when you only do it for a day or so at a time and don't have to go shopping/clean the house/help with homework (anyone who can get that wrong needs to take a serious look at themself) but hard work doing the IMPORTANT things that set them up for life especially without support and whereas dads reward is instant ours will be long term when they turn out to be ok adults.
Its just done to kick where it hurts, kids who live with both parents will have some other method of hurting them, ours use the other parent to stick the knife in.

Might be worth thinking about an extra night at dads if he'll have them, give you some time to build up a social life again. I long ago came to the conclusion that my unsupportive ex was nothing more than a piggy bank and a babysitter and use him for those as much as I can get away with...don't put it like that to the kids though obviously!