Help

I simply do not know what to do anymore in Dec 2017 we purchased a vechicle through the Cmh group and it was financed by mfc over the last year our circumstances have changed and we are not able to afford the high monthly payments. We have tried on numerous occasions to trade in the car and buy something else and all we get told there is a shortfall and there is nothing they can do to help us. I am not sure what to do anymore. Could you please assist us as I don't know where to turn to anymore