Go fuck yourself asshole! Just quit! Oh yeah, the three kids and their mother who won't go get her own job leaving you stuck in a job you can't stand that is going to bring the end of you...
My ex quit his job not long after we broke up as a deliberate act of revenge at the time and has not worked a day since. So yes, being the sole provider for your children's future is hard.
I also left him with everyhing when I left, so he not only had a wife that left him with everything financially and all possessions, but also one who had to take financial responsibility for the children he primarily chose to bring into the world through his manipulative behaviour.
I've worked some jobs I hated and taken pay cuts for stability at times. Things do pass, but yes, they suck at the time, for sure.
How old are your children?