How do I mentally persevere through the last 5 years of work?

I'm on track to retire in about 5 years. I just had my mid-year review and the things they are asking me to work on -- I just don't care about. For example, they want me to refine my project management skills. Totally fair critique and ask of me. The problem is, I don't really want to or care about being better at it. I've been working for 40+ years and have reached some success in my field. There is nothing left career wise I aspire to be or do except coast into retirement.

I have a great WFH job. My boss is wonderful. I've been there 10 years. My work is valued and respected. I get regular cost of living raises each year. I have decent benefits. I believe I am what the kids are calling a knowledge worker. I have nothing to complain about other than the work is occasionally tedious but daily just feels like a grind because I know I can walk away in 5 years and I am just kind of white knuckling it. While the work I do is interesting, nothing I do is interesting to me anymore. I just don't care. I'm in a position where I rarely make decisions but am often consulted for my opinion/analysis, and for the last year I have been defaulting to whatever everyone else wants to do because I just don't care what they do as long as it doesn't impact me in a negative way or is anything unethical (which never happens here). I legit don't even want to have my brain think about what they want a decision about. It makes me angry that they want me to think. If we had nationalized healthcare, I could retire today, which stirs all of my anger about billionaires.

I can fake a smile and maintain professionalism in all of my work interactions, and I get my work done, but I am hating every second of it. It's not the actual job, it's the fact that I still have one and need one for 5 more years. A different job would just be a different job with the same feeling, and I am too old to voluntarily walk away from the good thing I have just for something different. And honestly I don't think I can get a better job than the one I have right now all things considered.

I don't need life advice -- I eat healthy and have a therapist (for other things and I am not muddling that work with this), I exercise regularly, have many hobbies that I do when not working (which actually makes this worse because I would rather being doing all of the things I love doing), have friends and a husband and a social life.

I'm not depressed --- just more angry that I have to get out of bed every day to still do this. I know this is all in my head. But how did you stop feeling like you were white knuckling it for the last stretch? Or is it just what happens and you have to live through it to come out the other side. Am I destined to just smile hate my way through these last years?