You are not rude. Ever. You have to do what you have to do to survive. You can't fix your mother's problems----I don't know if she can or will.
I am reminded of my late brother in law who did take his own life---when he did that he was no longer the person he had been, no longer reachable, it was terribly hard on his kids, my kids, everyone---because we could remember him overcoming his addictions, being healthy, being the favorite uncle, the best---and in the end there was no reaching him; his poor choices took him to another place where nothing could be acknowledged and all words were lies.............................
Years later, I can say that everyone survived and is doing well enough, even better; but it is still sad to have the "could have been"s drift through now and again.
Sometimes, there really is nothing we can do to help another...
((((hug))))