It took me a few months to feel better after resection too. I think it's probably normal. Best to just talk it over with your GI.
Hope you feel better soon.
Female age 37 - two kids, age eleven and fifteen.
Colon Cancer - DX March 2013
Age 34 at DX - Stage III B
Resection surgery -May 2013
FOLFOX - June, 2013 to Sept, 2013
5FU plus leukavorin Sept, 2013 to Dec, 2013
METs liver and lungs discovered Sept, 2015
KRAS - MS ?
FOLFURI plus Avastin - Sept, 2015 - current.
Art therapy January 2015 to current.
CEA at recurrence:10.1/august, 2015
CEA: 1.9 February, 2016
CEA recently: 10.2 December, 2016