It's horrible isn't it. Flo was almost 14 too. I'd had her since I was 8, practically all my life. or almost all of my life I can remember properly.
Sounds weird and I wouldn't have expected it, but getting Jess so soon after has actually really helped me I think. Instead of everything being a really sad reminder or Flo like everything was when my friend died, things remind me of Jess. Obviously I still think about Flo alll the time, but not in that horrible constant way I used to feel reminded of Sophie when she died. obviously a cat and a person are different, but I think if I didn't have Jess now I would have coped with thios a lot lot worse. Also Lily has helped.