No replies to this? That surprises me...
I can emphasise with how you feel DayOne. We all have times like those in our lives and while it may not seem like it now, they will pass. The important thing to do is learn from the experience. Note what isn't working and try something different.
In life, when we are faced with a decision, we sometimes think we have just two options. We paralyse ourselves into thinking if we make the wrong choice now we can never find our way back.
The truth is is that in every moment we are faced with choices and - as the Baz Luhrman song says - they are half chances. That's not bad odds really.
You have to remember that whatever it is you do in life, if it causes you PAIN you take ACTION to change it. If doing the same thing is always bringing the same unsatisfactory result you KNOW you have to do something different.
If you changed jobs and you MAY have an equally bad experience - you may also have a very rewarding one. How will you know unless you try? It's still YOUR choice.
Good luck buddy!