Mum update or when medicine gets it wrong

This isn't an easy post to write but it's something I've wanted to record for a while. People ask for updates about Mum and there isn't an easy or succinct answer so forgive the long post.
She would've died several times during the last few weeks, well months really because she's been in hospital since the end of March, had it not been for medical intervention. And, on the surface, this seems like a good thing. While it has bought us some time with her, it is at a cost.
After numerous theories and tests we aren't much closer to really knowing what is causing all of her medical problems the most immediate danger being inconsistent breathing. The doctors change their minds constantly but the latest is that she has three potential problems or combinations of these three: Parkinson's syndrome, slow growing benign tumour in her brain and an as yet unidentified additional progressive neurological condition.
Not suprisingly the prognosis ain't great. The best we can hope for is that she gets well enough to leave hospital and go into a nursing home, although a doctor said this week she may never be well enough to even do that.
Which comes back to my comment about the medical intervention. Modern medical science is a wonderful thing but sometimes the balance is horribly wrong.
My Mum has essentially been kept alive so she can die slowly. Now that sounds melodramatic but it is true. We found out recently that when she was transferred to Papworth they were struggling to keep her alive, so why did they? Just a couple of weeks ago she was critically ill, had to be bagged and ended up back on the ventilator she needed when in ICU at Peterborough. So why do it when this is about the best she is going to get?
I firmly believe that an animal would have been treated with more dignity and compassion than Mum.
A good day for her is maybe sitting in the chair beside her bed for a bit - outside if its warm - a bit of suction ie a tube inserted into her lungs to get rid of the build up of mucus which is a pleasant for her as it sounds, maybe the occasional need to be bagged to help her rid her lungs of a build up of CO2 which she can't always get rid of herself and a mask or venitlator to help her breath when her O2 levels drop. She might even have a panic attack where she feels like she's suffocating. That is a GOOD day. And she is only going to get worse, slowly or get an infection.

Along the way the doctors have agreed to a DNR, we've even had palliative care nurses involved and Mum has planned her funeral only for the doctors to change their minds and intervene when there was a crisis.
They have now stabilised her enough on anti-seizure medication to finally remove the trachy tube but they don't know how long this medication will keep the symptoms at bay. They've talked about not ventilating again (ie sticking a tube down her throat or doing another trachy) if she needs it but then we've been there before.
She still needs an oxygen mask at times and not one of those flimsy plastic ones, this looks more like a second world war gas mask which she can't put on without assistance. She's still hooked up to lots of machines and taking copious amounts of medication.
It's horrible seeing her suffering, she is frail and down to skin and bone. It breaks my heart. And on top I am so angry with the doctors for putting her through this.
Every night I go to bed hoping that she has a major breathing episode, that the doctors can't stop, to put her out of her misery. Mother nature, after all, has been trying to do it for nearly three months now.
When all of this is finally over my sister and I have vowed to do whatever we can to change the system so that no one else has to endure this and no one else's family has to standby helplessly and watch.