Sudden surge of frustration

It seems like my anger still boiling, especially I thought about how he could ignore the welfare of his children, and his parents nonchalantly thought my single income could support the kids and myself.
Last night, I did my calculation and realise that I left a meagre income to survive for this month. I never get for myself anything other than groceries and for the children. Somehow I feel trap, I want to spend quality time with the children, but financially strap. I need to get another job to tide me over. Tuition used to be my option, but now holiday usually no assignment, and economic isn't rosy. Frankly speaking not too optimistic.
Do I really have to find another job? But what job...I don't want to be away fromhe children too often...
I don't know what am I suppose to do. I must give it a thorough thought???