I'm Lucy, and I'd be happy to answer your questions today. I'm sorry to hear that this happened.
A person is legally considered to have read, understood, and agreed to everything in a contract that he signed. It's unfortunately not possible to use "I didn't read it before I signed" as a reason to invalidate or cancel a contract.
However, if circumstances have changed materially since you divorced, and you can no longer afford to provide her with insurance, her income has increased significantly, she has remarried, or she has gotten a job that offers affordable health insurance, you may be able to file a Motion to Modify Judgment, asking the judge to change it. An agreement that you'll pay health insurance is a type of alimony, and alimony can always be modified when circumstances change.
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