MargeretX, the pain is really awful, I know . I cried and cried when we had to have Lucky put to sleep (kidney failure) a couple of years ago. After a couple of months we missed having a cat so much that we went along to our local cat shelter and were able to adopt another one from them. An adult female who had been found with her kittens underneath a shed....the kittens were homed by the shelter, and we now have Daisy, the mother. It's early days for you to be thinking of that, though.
Tomorrow is the first day of Jasper not being there with you, Margaret, but he'll have had a wonderful life with you.