Hi Ruth403,
First let me say I am truly sorry for the N's you are having to deal with. Dealing with them is nothing less than insanity. I admire your compassion for your daughter. I'm grateful my Grandmother stayed connected to me. She is one of the reasons for my sanity now.
I have been greatly helped in navigating the world of N's through the 12 steps, I go to Al Anon, and therapy. The N neighborhood is dangerous and I will not travel there alone. I still have a long way to go before I'm done with therapy, but I have gotten a lot better. I do not take insane rides with N's anylonger.
My heart goes out to you. I encourage you to take care of yourself first. You are worth it. What can you do for yourself today? Even a small offering of love to oneself can make a difference in a day.