Worried about recurrence

Hi, I am a three year survivor of Stage 3C invasive lobular.  It was in 10 lymph nodes.  Recently I have been experiencing more fatigue than normal, numbness in my arms at night, more pain in my upper back and my muscles burn even after little effort.  I also found lumps in my armpit on the non-cancer side.  I have had a double mastectomy, one was prophylactic.  At ultrasound was done and two atypical areas were found that were significantly echogenic.  A tumor is not ruled out.  I saw my oncologist and he sent me to the surgeon.  I saw him today and tomorrow is a PET/CT scan.  I knew the chances of my cancer coming back were pretty good, but I am still depressed over this.  I know it may be nothing, but my gut feeling is usually pretty accurate.