First, sending you hugs and hopes for peace and calm. Sounds like you have a lot going on in your life, and it's no wonder you are overwhelmed.
I run a cat sanctuary. I was involved in rescue for many decades and finally realized a long-held dream. I bought a small piece of property outside of the city, and moved all of the colony cats out here into a sanctuary for them to live our their remaining lives. Many of them are quite old and some have health problems. They were the "unadoptables". They are in a large confined area where they are safe from predators, etc. They have a heated and cooled area, as well as several "catio" areas where they can move about. It's big enough to accommodate well the number that I have.
I lose them regularly because of age, etc. It hurts like hell. It impacts me in ways that I don't even realize, I think. Then, of course, that coupled with all else that is going on in the world with Trump, etc., there is simply a great deal of sadness.
I cope by trying to remember the purpose of all of this, and by simply putting one foot in front of the other. The ones still living need me, and I am determined not to let them down. I love them each and every one, individually and completely. I no longer take in any new ones as I'm old and I need to finish what I've started here without adding more to the equation. I think when you are actively rescuing and you have the "highs" of getting one off the street, into a home, etc., that mitigates the "lows" of losing one. But now, without the "high", I have only the "low" of the loss. It's been a mind game to keep myself sane and figure this out. I created a garden area behind the cat enclosure. I spend a lot of time out there just sitting and thinking. I've worked hard and made it beautiful. It's my safe place, and it helps having it.
Wishing you all the very best...