I feel sick

I feel sick - my head is pounding and most of all I never thought, he would do this to his children. Today I check my bank balance and have had to phone the csa. Why? because the payment was missing and my mortgage is due to be paid monday. After two phone calls I discover the reason the payment was missing because my ex, has given up work to claim benefits. Im paying the mortgage and without the csa payment, Im going to struggle - I think he has done this in order to force me to sell. I don't know whether or not I my head is going to explode or I want to be sick first and god only knows