No experiences of dogs so won't offer any advice there.
From what I surmise I think it's admirable that you have taken on this dog with all her problems and you have clearly had her welfare foremost in your mind. I think to continue to do this, and to also prioritise your welfare higher, you should allow her to be re-homed somewhere better placed to meet her needs. It is a very strong step and a sign of your care for her admitting that you might not be best placed to look after her.
This is different but my girlfriend had a high emotional attachment to a pair of cats but they lived in a flat with no safe access outside. She could see it wasn't ideal and finally agreed to let a lady in her parents village who wanted cats to take them on where they had the quiet country life and could go outside. Although she misses the cats and felt at the time she was derelict in her duties to the cats, she is much happier now knowing they are happy. At the time, she needed the cats more than they needed her.
Anyway, good luck in resolving this. I hope your feeling and happiness take more prominence!