All those emotions
Oh dear, forget Guilt, you have absolutely nothing to feel guilty about. We all feel it, and some of us may have a little niggle about it, but from what you say you have absolutely no need at all. We can all kill ourselves trying to care for our loved one, and then who takes over when we are dead? No, love, don't feel that amount of guilt. What else did you say? I've forgotten, but you really mustn't carry on like this, you deserve better for yourself.
Yes, keep your job, your mum wouldn't want you to give it up. I'm a lecturer, and we have the same stresses, contstant appraisal, all the bloody paperwork and deadlines to me, but if you like the job, as I do, stick with it.
Failure, no way you are a failure. I think what you mean is you've not been able to solve the problem. I can run with that myself. The point is there isn't a solution to the problem. Or at least, the solution does not lie with you.
I am glad that you think so highly of your mother, and can appreciate how distressing it is to see this wonderful woman in such a sad situation. I have no such relationship with my mother, she has never supported or assisted me in any way, but I still feel the same as you, that I should do the best for her, and I will. I feel even more guilty cos I don't love her! But at the end of the day, it is about doing what is right for you and her, and it is obvious that you will do that.
Good luck, get a good NH and reassure yourself that you have done your best.
Let us know how you get on.
Much love
Margaret