I understand and feel for your loss. I remember when I had to put one of my older cats down due to her not doing very well with her age. Actually, she too, had been suffering multiple tumors and the sequential episodes of surgeries was making her life miserable. I know how hard and devastating this can be. You didn't just lose a pet, you lost a companion, a family member. I know it will take a while to register that he won't be with you anymore, but the memories you shared can always be cherished. He is now in peace and lived a happy life. He was a lucky kitty to spend his life with you :3

my best wishes and deepest sympathies to you.

I am so sorry. I was absolutely devastated when my last cat Max passed so I know what you're going through. I hope you'll feel better soon.

I feel with you. it's not easy to have to put a beloved pet to sleep, much more so if you've known it for years (or, as with me, grew up with a german sheperd).