@Elf, I got pet insurance for him, but unfortunately it wont cover any issues associated with his gallbladder. I now know to get pet insurance for all future pets though.
It felt unfair to lose him when I had already lost my other cat unexpectedly and traumatically 5 years ago. Plus Oliver has only been in my life 7 months. He has to get better!
@Fairytale, he really was. I seriously thought we would have to put him down. I am pretty optimistic now, just hope he does ok once he gets off his meds we have been using to treat him.