Yes, Ornery said it.
Expect nothing, then anything you (plural) do get from him of a positive nature is a bonus.
Plan your life and your kids' lives/time/support at university as if he doesn't exist. Yes, as Ornery said, go and talk to student support, etc, and make sure they know the situation and ask them for every bit of help you can get.
But something else Ornery said made me think twice. The model of this:
Ex-husband and new wife (often originally the OW and/or best friend of original wife ...) - they are selfish and use money to control.
Mother of children - victim complex, thinks everything is his/her fault, despairing/hopeless/can't get herself out of it, eaten up by resentment, etc.
Hmm. This isn't just a one-off, just the people Ornery knows. This is time and again how the woman left holding the baby(/ies) feels. And there is definitely a way through it, and you need to get on with it and be one of the ones who puts it behind them.
It's a bit like there being commonly-experienced, clearly-identifiable stages of grief. There are common feelings when you've been treated badly. BUT, and this is a massive BUT: if you want your life back, and you want your children to be happy and successful in the way they have deserved to be from when they were tiny, then you HAVE TO lose the chip on your shoulder. YES he has rejected you. YES he has run off. YES he's using money to control you and make you feel bad. YES you feel beyond angry at the position you've been put in, through no more fault than your relationship having come to the end of its life.
So you have a gigantic, totally justifiable chip on your shoulder. Noted. Anyone who loves you totally agrees that you've been treated badly. And there is no defence against straight abuse apart from ... really and truly walking away.
Regroup totally, with the kids. Do what Ornery suggests. Create a world where this guy doesn't exist. IVF - great - that means he was there to support you when needed. Now you don't need him. The kids are here. They're with you. Make him redundant. Sack him. Show him the bloody door. You don't need him. Really erase him. Gone.
It will seem difficult or impossible sometimes, but the moment you stop thinking 'he needs to help out with this cost' or 'why am I helping my child carry 25 bags up 4 flights of stairs in student halls when their dad should be here helping??' etc etc ... the moment you realise that he just isn't there, doesn't exist ... that's when it will feel much easier to sort out the money, and much better climbing up those stairs.
It's all a cliche - the advice that to move on you have to go through the motions of the right steps to take, even if unconvinced, and then after time you'll start to feel better, and then it will get much better, and one day you'll have your life back - a total cliche. But cliches are such for a reason. So many have had to face this same journey before. So just do the same thing - don't reinvent the wheel, and don't feel stuck - just follow the path out. Someone's dropped some crumbs to follow. Hell, there are massive signposts and sanitary facilities and a Prosecco bar on the way out of these woods - SO many have been here before.
Follow the signs, do what we're saying, and sooner or later it will work, and you'll be out of this, and it won't be able to hurt you or your children any more.
Thank god the bugger has gone - let him go. Be glad he isn't being a pain in other ways. The way out is relatively easy. : )