In all honest, no one but you can decipher a bad relationship and or being with a person who is struggling with PTSD affliction which can manifest in so many different ways.
In my view, the best way to be in a difficult situation, especially one with unforeseen end to the health issue, is you must become a stronger person for yourself. If you start to have victim mentality, bringing others (friends and foes alike) to your relationship, struggle emotionally on daily basis, and all these other stuff, the PTSD becomes the chicken and the egg. Are you in a better position you were before or after or are you also colluding in his recovery, and/or are you giving up your self agency to this person or are you even contributing to his lag of healing?
It is not easy. No one knows you or him or the dynamic. Get a therapy for yourself so you have a support and you have a place to take care of yourself and you learn how to be better for you first and foremost before you focus on him and lost track of time. This is no different than a caretaker, empathy and support are not unlimited and we can all run out of them. So do not burnout yourself.
Remember, he can leave you too. That is an option. So if you give up on yourself and still he leaves you, what do you have to hold on to?
Be kind to yourself. Get the support you need. Stop gossiping about his issues to your friends which only adds fuel to the fire and also he may not be oblivious to this and probably it adds to the discomfort and trust issues.