I kinda know how you feel. My beautiful baby, Cookie, disappeared in April, and I haven't seen her since. However, one of my friends has. She saw a cat that looked like my cat, then she called "Cookie", and the cat came. But as it came across the road...
A car came and hit her... 
I miss my baby SO much! May StarClan be with her!!! (I <3 you Baby Kitty!)
Anyway, I hope Jasper feels better. I LOVE black cats, and I think they are beautiful. But look at the bright side... At least he isn't dead, and he's safe, with you.