I understand. And on top of this, the superficial contacts we all have during our life. Most of them disappear - even families, kids... I have gone through this. Just like you I was from a certain moment on no longer able to work - but for me it was 30 years abroad and many years in war torn countries. Sudan broke me (when the civil unrest started) and ever since I have to fight.
I am happy for you, that you have your own place, that you can take care of your parents. If you are a lawyer - maybe I would do something social, like consumer protection or so. You can be free, no payment - but of great use. And you would find more reliable, honest people. But that is just a fantasy of what I would probably do.
Anyway, just to let you know - you are NOT alone in this world and there are more people who understand you than you might think. O am one of them. And if by any chance you ever come to Spain - be sure to contact me.