Quitting after maternity leave

I’m curious who has experience with this. I am going out on FMLA and using short term disability benefits paid for by my employer. I’m in Massachusetts.

I don’t have any other benefits thru my employer, they just offer the disability.

Covid has really put everything into perspective for me- I know businesses need to worry about money but when you work for a non profit that is supposed to care for people with disabilities then you would think the company would care more about their people and those they serve but they don’t. I’ve been working 60+ hr weeks since March without more than a day or 2 off for doctors appointments and no overtime pay.. and now even the day before my maternity leave is set to start (I’m being induced tomorrow and they know that) they are still working me like crazy and expecting me to work tomorrow even though my last day worked is technically today.

So I have been thinking about just resigning when my leave is over.. but idk the legality of things.. I’ve read that sometimes you have to pay back benefits but not sure if that includes disability payments.. so I’m curious if anyone has experience who can help me.