She doesnt care for/about me at all. 

Perhaps she hides her feelings well. 
Pain and fear make our souls suffer, and they don't allow/stop(1) us from breathing, from filling our lungs all the way. 

I won't do this until the end of my life/for the rest of my life.I think this is what you mean.

(1) I think 'stop' sounds more natural 'don't allow', but both are correct