wow, 20 years is quite a long time, I can understand the pain you're feeling. very normal for animal lovers like us.

I agree with QOP, loss will never leave because only gone but never forgotten.

maybe this will help you, recollect pictures of your precious sweet kitty, make collage or do a mini-scrapbook, especially frame a favorite picture of her/him.. that way it has made me feel my little fuzzyboy, edges (sixth face in second row down in my signature) is still around, mostly in my heart, watching me with his cute eyes, smiling.. at first, yes I couldn't get over with cryings and pains but later I started to see him smiling. try that? something to heal the pain better way.

for spike, love him as much as you can! poor her if she doesn't know what's going on, she would need you the most right now.

hugs to you.