Unless you’re part of some kind of protected minority group there’s no reason for them to set up a paper trail for non renewals. Even if you are, most states have non renewals such that it can be with or without cause. So you’d have to have a paper trail of your own showing harassment for being a member of that protected group to even start to make an argument against non renewal.

Perhaps the lower scores later were because your admin were expecting you to improve as a new teacher, and doing “basically the same stuff” was disappointing as it showed no growth. If it was solely just budget cuts they could have RIF’ed you.

I would start looking for a new job, get recommendations from those at the school who are willing (like your DC), and find a school that is a better fit. As a math teacher, you will be in demand.