Can I file a motion to readjust child support if I have been left destitute?

I lost my job 2 years ago and was bullied into accepting a child support order for which I had no means of being able to make much less be able to take care of my children when they were with me. No income and other parent filed to change custody because I couldn't afford our co parent counseling thus further limiting my time with children though prior to separation I was the main parent. Can I file for the support order to be changed because of the economic hardship as the other parent has a 6 figure job while I have been left with a negative bank balance? Also, because of not being able to afford representation, I did not realize when we made this order 3 months ago that we were supposed to exchange financial info for determining when ex's attorney said to just accept the deal or else