Help help help!!!

I have 75,000 in credit card debt on 8 dif cards, one is a credit union with $24,000 at $500 a month I have heard that credit unions do not typically negotiate, in order to start debt settlement you have to stop paying on all your credit cards, I do not know what to do. That payment would take $500 dollars out of my monthly savings for settling other accounts. Anyone have any advice????