Grammy, let me first offer you giant cyber hugs and then a big shout to say "You are normal!" IMO, you might tell your DH to back off, and tell him to "just get on with it" after going through what you went through. I guarantee he'd crumble. NO one can tell you how you should feel and I bet every one of us has been in your shoes. There is a big "let down" after treatment and a tremendous feeling of vulnerability sets in. That is the time we get scared, start second guessing ourselves and our docs and we may even cry a little. I was sure I had mets to bones, brain, liver and lungs within a year after tx ended, and I considered prophylactic mastectomies. (I did not really have mets). And I cried plenty when the fear got to me, and the feeling of "OMG, did I really have cancer?"
I think time is simply one of the best healers in relation to cancer. It will get easier, but it takes time. And you may have a step forward and 2 steps back, it is all ok. I think many here would agree that the first year after cancer is a very frightening time, and no one else understands. They act as if you had a bout of the flu, and you are done so just move on. They don't know how this impacted us and rocks our very core and influences everything we do going forward.
In due time, it will be easier and you will think less and less about it. I used to tell myself that my goal was to go a whole day and not once think of BC. THen I thought as long as I post on the internet, that won't happen....so I needed to reframe my goal. I changed it to more of an acceptance and peace, than to trying to ignore it. BC changes every one of us, and we have to find a new normal. It may be hard, but you'll get there.
And if you find that it is too overwhelming or the anxiety is interfering with your life, then it is time to talk to a doc or therapist about therapy or meds.