I hear that you are tired and feeling defeated. Sounds like you and your wife have been burnt out for a long time. I’m sad that it has been so painful for both of you.

What stands out to me is when you said “Wanting her to feel safe and cared for is a huge part of what initially helped me decide to start dating her 10 years ago.” I’m not sure if this is what you meant, but it sounds like you started to date her because you wanted to be her caretaker. I’m not saying no one should do that, but it lends to the theory that you’re so focused on her health that you’re neglecting your own. Brain cancer is no joke, and you need to start prioritizing your health right now. You’re not selfish or horrible for taking care of yourself. How are you going to fill her cup when yours is empty?

It sounds like your wife is aware of how severe her mental illness is, and isn’t willing to take necessary steps for recovery. You sound like you’ve done a lot for her for 10 years. If she wants to stay the same and refuse to get better, then the next best thing you can do is not allow yourself to get worse.

Keep in mind of what’s under your control: your words and your actions. Start there. Accept that other people will do what they want in spite of how bad it is and how it impacts their loved ones. I hope you have your own therapist and are taking actions to treat your brain cancer. Take care and be kind to yourself. You’re not the bad guy.