Hi Stacie,
You've heard from some very wise folks. I'd be reiterating what they said however it's true. Living in fear is not living.
From your post, it seems to me that the fear you're experiencing is causing you a great deal of stress and angst, to the point of causing you to withdrawal from your husband at a time he needs you to be joyful along with him at such great news of being NED. Perhaps some counseling would be appropriate under the circumstances. Cancer can be just as hard on the caregiver as it is on the patient.
Positive thoughts and prayers
"T"