Dear Hops,
I am so sorry that you are going through this. I think that all people have ambivalent feelings in all relationships. I could be wrong,but I think that it is human nature.
The medical field prescribes "things" as they did for your mother ,often, to CYA. Often things are given not in the patients best interest,but to 'prepare" for a potential lawsuit. Families can come in later and say that they were not told to do a certain thing and the patient died. then, The facility(PT) or doctor is sued. There are lawsuits( and winning) over the silliest things.
IMO, your mother as a 96 year old person deserves the right to follow what her body wants,not some medically prescribes routine. Think of yourself-- which regimen would you want to follow?
I think that "normal' guilt is making you doubt yourself. You are having normal guilt and normal ambivalent feelings(IMO).
I would say that the most important thing that you can do,now, is to trust yourself.
(((((((((((((((((((Hops)))))))))))))))))))))) Love Ami