So, you are saying you and he had a court ordered child support agreement that he paid in good faith and you just never got reviewed to get it raised? Are you saying the judge raised his support ot $950 monthly and subtracted the $200 and that made it $750? Or the amount it is raised to is $750 and the $200 isn't counting at all? I would agree the $550 is the amount he legally owes if it is to be paid retroactivley. Plus if the judge takes the amount into consideration and charges back/late fees etc...it sounds so confusing and I understand why you want a peaceful resolution.
Then it seems to me that he has the right to be annoyed. If you wanted more child support why didn't you ask for it until 2 years ago. I think that from that time forward he should have the full higher rate but not previous to that point. He was following the court order, now there is a new one.
$750 owed - $200 paid multiplied by 14 years is nearly $100,000.00, no one is able to pay that without losing everything. Plus his wife should own half of everything and she doesn't owe anything.
Child support is for the things you listed above. He should have done more, of course, but he didn't. We are fortunate that one of my grandkids dad's gives his child $50 every birthday and again at Christmas. The plan is that when she is older the gift will be a bit larger. We let her take the card to Walmart and pick out some of it herself. Part of it we buy something she has been wanting, wrap it up and she opens it on Christmas, I put the card on it from her dad to her. That way she doesn't know he just sent the card and nothing else. I know she will realize later that he doesn't care but I want her to believe for as long as possible. Her dad has never missed a child support payment and the Child Support Enforcement does a regular pay raise every year. The other dad doesn't even see his son and he lives in the same town and only pays the minimum wage support. It's helpful but not much.
I think you have a hard decision here, talk to your attorney about a resolution. You can unite with your ex and tell the court you have reached a joint decision, one that both of you agree on. Any extra money you get is a bonus. Hopefully he can pay at least half of what you are owed and you can go on from here.
My ex is raising on of our grandkids and he asked talked to the dad about a cost of living increase and they decided on an amount, my ex filed the papers and then the judge decided to not accept it and raised it nearly double the amount my ex asked for. My ex told the judge that his amount was unacceptible, that they didn't want or need that much, the judge refused to put the amount to what he and the dad had decided on. My ex finally told the judge to go ahead and he would just write a check and return the amount extra to the dad because it wasn't what he wanted. The judge finally agreed. BTW, my ex and his wife are older and both have high paying jobs and REALLY didn't need the higher amount at all.
I feel really bad for you, and a little bit for your ex, it is a hard decision you have to make and you seem nice since you care about the whole picture, not just yourself. I hope you can find a peaceful resolution to your issue very soon.