What's the worst thing that will happen if I refuse to sign the divorce papers?
You'll keep on waiting for that other shoe to drop. And you'll be paying legal bills. You'll be stuck with a person who doesn't want you, and you'll not be able to move on with your life and be truly open to someone else. You're asking to stay in a dead relationship, whether through unfounded hopes they'll come to their senses or retaliation against some new relationship that they've found.
Neither is emotionally satisfying to you for long and if the tables turn, and you find someone, they may decide to not sign and let you hang.
Handle this like a adult, divorce and leave the bad behind.