I also advise taking the snake to a vet just to be on the safe side.

You have to understand. The people on this forum are very passionate about snakes and most have been working with them for years (some more than I've been alive). They are only trying to advise what is best for your snake. I understand you've been keeping your snake for years like this and until now, had no issues. Just because this is the case, doesn't mean it is the proper way to keep the animal. Letting the snake roam free in your room is very dangerous, especially with a cat involved. Ball pythons are very secretive animals. They like small, dark, warm places (which is probably why he enjoys your blankets). It is not the roaming around he enjoys, but the warmth of the blankets and the darkness itself. Letting him roam on the bed is fine, but always keep an eye on him. And while the snake is out of his cage, it is best to keep the cat out of the room until the snake is put back into his enclosure. I actually keep every single reptile I have in a room that the cats are never allowed into. Some of my cats have high prey drives and a loose snake would be an exotic meal for them. I'm not saying your cat would make a meal of your snake, but there is always the CHANCE. And as the one responsible for your snake's well being, why take that chance?

Just my $0.02. I hope your snake is okay and there is no damage.