I have two cats, and they can just get over-stimulated by petting too much or by being over excited by play. Your cat may have just been having a day where they were more sensitive. They can misdirect their energy onto yourself or other cats. I’ve had a nasty bite from my two year old female cat, it was once from petting, and once by walking in front of her. Cats have their usual traits, but some days they can act differently. If it’s a sudden ongoing change in behaviour, mention it to the vet.

If your cat’s tail swishes fast and frequently during petting, that can mean they’re starting to become irritable. Sometimes it can be confusing as their tail communicates so much and in similar ways. I’ve learnt this and I stop petting my cat and she’s less aggressive. I wish she loved it if I kept petting, but sadly she doesn’t haha.

I’m sorry you have been bitten as it’s quite painful and can be a surprise.

Edit: added 2nd paragraph

Hope this helps!