Social Security does not perform 'audits' unless there is a reason to reopen a previous decision.

I cannot envision a scenerio from what you say in which SSA would reopen your husband's favorable decision.

Your loss may be fueling your fears, so do what you need to do to work through the grief. But it is a process that takes time. Give yourself time and try hard to let go of things out of your control, like the last poster said.