Don't discount the emotional and psychological toll committing yourself to chemo can have. It's a big deal.
When I get super stressed I present with the classic fight or flight responses--I either start climbing the walls and attacking everything that moves or retreat to bed and assume the foetal position.
Everything you feel is real and valid. Try to view this as a very interesting personal experience which will pass. Keep plodding forward and you will eventually trudge out into some form of normality. Albeit with dodgy gut flora and wonky feet (in my case)
It's all pretty shit, but it is our best chance of survival. Mxx