['I was really scared about the possibility of losing my cat to a bad illness, but I was lucky that the vet worked hard to find out what was wrong.']
Oh wow, I'm glad the vet was able to do that. It must have been scary.
I was really scared about how sick my cat was and, at first, feared that I would lose him. But the vet I took her to did some research and found out exactly what was wrong with my cat.