Emergency care for Columbo

Our cat Columbo is about 5 years old. A few days ago he started having a hard time breathing, and we've had to seek emergency vet care for him, which has wiped out our entire savings account, and we aren't sure how much more care he might need before he gets better. We're both just really worried about him and terrified that we're going to get to a point where he needs care that we can't pay for.