Intervention or not? My Mother's Committing Suicide w/Food

I desperately need advice. My mother is over age 60 and obese. Like many American women, she struggled with her weight through life, but nothing like this before. She has given up on herself, she is depressed, she can barely walk, her health is crumbling rapidly, and any attempt our family makes to ask her about it ends in her crying and acting like we're abusing her.

She fully admits that she is an addict and runs to food to fill every void. But that's as far as she goes. She is unwilling to fix herself and comes up with elaborate excuses for why she can't work at losing weight. She and my father have been happily married for 40+ years, but I think he's nearly had it with her. As have the rest of us. Having to watch her fist down a dozen pastries after dinner feels like I'm watching her slowly commit suicide. I've never been ashamed of her having some extra weight on her but now I'm deeply ashamed of her obesity. I cringe when we're together in public because people actually stare at ME like, "a good daughter would get her mother some help". Last year I offered to bring she and my dad on a family vacation and she said no because she can't walk. I told her she had a year to lose some weight before the trip and she looked at me like I asked her to model down a catwalk. So this is my dilemma...

Should I remove myself from her life? Or should I have an intervention? I've removed less toxic people from my life in the past, but this is my mother! I want to travel with her and watch her play with my children, not watch her die of an addiction. It's so bad I can't even look at her when she's in the room. Even my little kids ask "Why is grandma so fat? Teacher says that's unhealthy."

One of the problems with intervention is that she's convinced herself I have no credibility because I've always been thin and have no addictions. Whenever it has come up before she always starts with "You don't understand because you're skinny." - or so strong willed, etc etc. When I try to show her obese recovery stories she always has an excuse like, "I'm older than her", or "shorter than him", or "she has a different body type", or "he has a fighting personality and I don't"... Then the excuses expand - "I can't afford to eat healthy", or "your father won't eat diet food", or "I 'd feel silly going to a therapist", etc, etc...

The thought of telling her I'm removing myself from her life makes me cry just thinking about it. But I'm spending far too much time miserable and frustrated because of her and it's starting to take its toll on *my* marriage and children now.

Any advice you can give me on this would be most appreciated.

I don't think removing yourself from her life is the best idea. Who knows how long she has left to live, and when she dies you'll feel awful for not having spent more time with her.
I'm not an expert, but isn't there some kind of medication that she could take? Meanwhile, you could work with her on reducing the amount of pastries.
btw I know this post is old, but I thought I'd reply in case you see it or if there's anyone in a similar situation out there.

I know this post is old, but I need to speak.
You could be my child
When he was about 11 years old I decided to have weight loss surgery (My thought being I could die on the table or give weight loss a chance)
I lost a lot of weight and went roller skating, played basketball, rode bikes and even went horseback riding with him
He is 22 now and I have gained most of my weight back
I realized there was a reason I had to be fat
due to childhood trauma I had to be repulsive to others
I am working through therapy and have started an art journal, because I fear someone would find my writing.
It is the most amazing thing, no more constant cravings, the weight is coming off and my goal is to move more. I know it will take time, but I am worth it and so is my son.