Worried

I am worried about my little ferret - I starting noticing he wasn't walking "right" and he has not been interested in leaving his cage which is really weird. I also made the comment to Mr. Man that I thought he had lost weight - I googled sick ferret and we got him some Gerber baby food and he seems to eat it and he tried to come out and play - poor thing was too weak to even get in his hamper. I hope it's not brain damage - but I held him and could feel is spine - if I don't see any improvement in the morning going to take him to the vet - like I can afford that, right? I can't not take him - poor little fella -