I think we all have our moments MB. I know I do. Soul searching and wanting to quit my job pop up now and again. There are those days when I wonder if I am truly happy and so on. The reality is that I can't quit work at least not without a plan B.
And I don't have to be the happiest man in the world. Just stable will do me fine. But I understand how you feel (a bit anyway)
Soldier on