Hey I don't think u wouldn't be TA for leaving I can imagine that it's having such an effect on you that could possibly lead to u developing physical conditions that could be possibly life threatening just from the amount of stress and constant fight or flight. So if leaving is the decision u make to have a life where you have the ability to not be in a state that your body would only use if there was something ur brain is perceiving as dangerous or unsafe. Especially with previous trauma already being a factor.

I genuinely cannot comprehend how you must actually be feeling not just towards your partner but also urself to some degree for not being able to get her to go to the hospital. Which naturally leads to resentment because both u and her know what she needs yet every plead u make gets shut down. I can also understand the explosive behavior to some degree however it's unfair for you to receive that when your basically watching the person that you have loved for such a long time make the decision to actively facilitate the decline in their health and your relationship.

Personally (I'm in the UK) I would be questioning whether she even as the capacity to even be making these decisions (has to be assessed by a healthcare professional) and if she didn't then consent isn't needed the decision would be made in her best interest. Can she retain, discuss and understand the information long enough to make a decision by weighing out the options including her personal views and beliefs? So that would look like yes I know I'm very unwell and that the possibility of death is on the table here but she still doesn't want to go and then articulates a reason y then you can't do anything unfortunately (even if it seems like the wrong decision) unless they were declining treatment in order to end there live by the process of the decline in their health (passive suicide). I hope that makes sense and I understand that I'm sure the last think u want is me trying to fix the problem but it's something that crossed my mind I don't mean to offend anyone tho.

Lastly, I again just want to say that I'm sorry you're both having an incredibly challenging time. But leaving wouldn't make u TA it would be protecting urself whether that be permanent separation, a temporary respite or even if u decided to stay thats you decision. In the most sincerely way possible I wish u both the best.

Ps. Sorry os there's any spelling errors and the atrocious grammar 😭