I lost my 18(?) year old kitty

When I first adopted him we picked him because his story was he was left at a fire station because the girls boyfriend threatened to kill him. He was my first friend moving out on my own. He took me from 20, barely knowing what I'm doing, to 38 and still kind of in the same boat but handling it better. He went the way I feel was best case. Just an old guy(I don't even know how old he was when I got him) no health problems, didn't have to euthanize from hanging on and starving, I got to hold him until his last breath. I'm a wreck I lost my buddy. There's no one screaming at me tonight and it sucks.