No words to describe it

For whatever reason we all wound up here, we are here, a painful place to be.  No two circumstances are the exact same, yet they are all so very much alike - heartache, pain, bewilderment, shock that our children can be so cruel and detached from the very one who brought them into this world, nurtured and loved them, and now they spit in our faces, and they feel completely justified in doing so.  There are no words to describe the pain and anguish.
I truly am old and broken, broken in body, mind, and spirit.  She is the only family I have and she could care less if I am alive or dead.  A scary place to be -- feeling alone -- if I died in my sleep no one would know until my body began to stink and the morgue would have me cremated and ashes thrown away before she would even know I was dead, and even then, this would be a relief to her.
As a single mom, I did all I could for her - worked hard, gave her anything and everything she wanted never once giving thought to myself and my old age and how I would survive, and while I continue to work at home as a transcriptionist, it's not enough and trying to find work at 65 has been futile,  yet she criticizes me ... "I can't take you in mother" ... "No, I can't help you mother, you're grown, you should be able to take care of yourself - it's not my fault you were a poor planner."
Still not sure how I could have planned any better.  I gave birth to her at age 38 - went through the pregnancy, birth, and all these years alone, doing it by myself.  There was no time to think about me, I was too busy thinking about her and meeting her needs.
Now she looks at me and speaks to me like I'm shit on the bottom of her shoe.  It hurts, way down deep, it hurts.  Even though I know I did the best I could and all I could, she has a way of making me feel ashamed and needy.
Two weeks ago she sent me an email saying ... "How about this?  Lose my number, my email, any means of contacting me until you take responsibility for your life.  I have no moral, emotional, or financial responsibility to you because of the bad choices you made in life.  You are the master of your own fate, not me.  Any future emails will be deleted and unread."
All I really needed and wanted from her was a phone call every now and then ... Hi Mom, you okay? or to maybe stop and see me since I don't get around so well because of my back and poor breathing.
I honestly don't think I'll be in this world much longer.  I didn't feel well to start with and now with the added stress and anxiety of all this crap from her, I feel even worse.  I feel hunger but have no appetite, I either can't sleep or sleep too much to avoid thinking since I can't seem to turn my mind off, and the anxiety and stress has caused my breathing to be even worse.
At this point, I'm most worried about Sarah, my kitty, my faithful companion who loves me no matter what I say or do, or don't say or don't do.  I cringe to think of what will happen to her should I die in my sleep or just die from my heart being broken into a gazillion pieces.
I am disappointed in myself.  I have always been such a strong, resourceful woman, and now I'm like an animal in the road whose been run over by an 18-wheeler, just waiting for the next one to run over me again and finish me off.