I can relate to your gorilla via my husband who finished his treatment for cancer of the pyriform sinus and neck node almost a year ago.
Every time he has any symptom occur his first thought is that it's cancer. I know that he will never be the same, we will never be the same, but in some strange way you learn to live with it.
On my hubbies last day of radiation treatment, the machine broke down, of course, so we sat in the waiting room for a couple hours determined to not have to come back and extend the treatment until the next week. My hubbie was so sick from the culmination of all the treatments - chemo and 39 radiation plus a horrible rxn to amiphositne, but he just wanted it to be the last treatment so we waited.
During the entire duration of his treatment, we always sat silently in the waiting rooms - oncology unit and radiation - never spoke to the others who were waiting for their treatment, almost like we were still in denial that we were there b/c he has cancer. During the wait for his last treatment, this woman came into the waiting room and sat down across from us. She was one of those people you see that looks bring, like she knows something about life - she was radiant. She started talking to us and we shared with her that we'd been waiting for the imrt machine, and that it was the last treatment, etc. I'm sure we looked desperate, as we were. She shared with us that she'd had treatment for cancer of the throat 30 years prior and that she's survived this long - she was in her 60's with no reoccurrence. She was back to be treated for another type of unrelated cancer.
I asked her how she had survived all these years. The one thing that she said to us that really stuck was that we should walk out that day and move forward, never look back. Don't think of yourself as someone with cancer, don't look back - move into the future.
I took that to heart b/c I had spent all the months in treatment focused on the right now, the what if it comes back, etc. It was almost like getting permission to think about the future again with my husband a part of it.
Anyway, after almost a yr of remission my husband has a suspicious node in his neck, so he's going to have his second pet scan in 6 wks to check for reoccurrence. Of course, he thinks it's back and we're worried. But again, I think we have to assume that like everything else, it's possible that this too could be nothing - scar tissue or benign.