I understand how you feel, we're not out of the wood yet with my DH's end of chemo CT scan today and one more treatment to go, and even now I wonder if any little thing could mean something is wrong. I told my Mom that every pain, sneeze, and symptom going forward is going to freak me out and she told me not to worry and that "anxiety is a sin" so I completely understand the lonely feeling part. It's hard when no one else in your circle can comprehend how you feel or know what it's like to live through this, and I'm just the caregiver. I've wanted to join a support group, but all the ones locally for caregivers are in the middle of the day while I'm at work. Maybe finding a support group might help you too?
I can't give you any advice on what symptoms to watch as we aren't at that stage yet, but if you are having pain or not feeling well talk to your doctor. After buying new shoes my husband suddenly had a red, swollen knobby part of his foot that gave him a lot of pain. I was convinced it was bone mets though I read it was unlikely, so John went to his GP doctor. She examined his foot, took an X-ray, and turns out it was just a run of the mill bunion. It just never bothered him before because he wears his shoes for years and they were so broken in. I felt a little silly but knowing what was causing the problem helped.
Caring for DH John, 41
DX: Colon Cancer, Sigmoid colon
Tumor type: Adenocarcinoma
Tumor grade: G2, Moderately differentiated w/invasion of visceral peritoneum
Positive lymph nodes: 6/22
Chemotherapy: FOLFOX (6)
12/17 ER and emergency surgery
02/18 Hospital w/ MSSA infected port, PICC line inserted, abdominal CT scan clear chest CT scan showed septic emboli & blood clots
03/18 Hospital w/ CDIFF
04/18 Chest CT scan clear
06/18 Colonoscopy Clear
08/18 CT Scan Clear, NEMD