I'm sorry that I dumped my grief upon you people but I'm also glad that I did. You are so kind and amazing for sharing your thoughts which makes this thread a beautify place. Reading the comments does help and I think it turns out to be something helpful to others too.

The grief haven't get better but I'm starting to get a grasp on it. I'm scared for being so alone the first time in many years. I tried to distract myself by watching shows and playing games. After a while I'd go check my cat to see if he's ok, before remembering that I won't find him anywhere. I'm, however, grateful for those sad thoughts and stupid habits as it assures me that my cat will always be with me. And that's way better than forgetting.

I'm sure my cat had at least some good time through out the 19 years (like the time we sleep together in the sunshine). It's sad to think that I can't give him more good things but it's comforting to think that he won't feel pain anymore. I think he doesn't care too much being the little asshole he always was. Fricking cats...

Maybe there doesn't have to be a point. Or maybe the point is to love and to help. I still don't have an answer but I'm glad that I asked. And I'm grateful that many of you who have it figured out cared enough to share your answers. Thank you, kind internet strangers.