How to care for a mom that you know needs you, but show her narcissistic traits more and more?

I have lived with her like this all my life, and my poor daddy put up with so much. She said jump, he ask how high. She never admits that my daddy or I ever helped her, or love her. She was in the middle of both my marriages, and has taken my youngest, now almost 32 year old son under her wing. He loves it, why wouldn't he? She has waisted and spent way to much on him. I have read so much on the subject, and not until a few years ago realize this was my moms problem. Now, now it is sometimes impossible, ALWAYS ABOUT HER, if I say my back hurts, hers is worse, if I need clothes, she needs them more. (And if you compared the two closets,,,,,you would know). I lost count on how many times over the years, that I told her all she cared about was herself.(not lately because of the Alzheimers). My daddy was very ill, asbestose related, I was not living in town for some of that time. But came home often to check on him. They said he needed he needed to be on hospice, my mom denied. After me seeing her tell him to get his own bow of cereal, and how he could not, I called and got hospice. Of course this was all her idea.....the list goes on. Alway her idea, she helped the most, all the neighbors and friends love to talk to her, on and on. I am going crazy!!! We can not afforn in home care for her, I do not want her in a home. And even if was ok with it, I would lose this house. My ex, brought this to my attention....her favorite this to do is say, I will let you, I guess just grew up with that. Or she will say, we need to, this means you need to wash cloths, go to the store, dust, etc. But not her. So tired of all her, telling people all she has done(even befor AD) ,and a lot not true, or exaggerated. I know her dad was a lot like this, just learned this about 20 yrs. ago. BUT, he put her on a pedestal. her out of all 5. She puts my son on one. How do I cope with this? I try to get out off and on, but i need more than a few hours away. Oh well. I read something someone else has said, they do not miss their mom now. Honestly, I love mom, but do not really like her, that is hard to admit. And i wonder will I miss her when she is gone? Not sure if this was a good topic, but yes I am burned out, tired of the AD, tired of her narcisstic ways. Just plain tired. She is only 78, will be 79 in August.