I will soon be six years out from my surgery. I am very glad that I refused both radiation and oxaliplatin, and only took four rounds of xeloda/capecitabine. Radiation would have killed my sperm production completely, and also hurt other organs in my pelvis. Oxaliplatin would have irreversibly damaged my nervous system.
I am living essentially a normal life. I even have got several children, including twins, without any help whatsoever.
Do not hurt yourself irreversibly for the rest of your life with over-treatment. It is not worth it. (Yes, there is a small extra risk that you die if you refuse the over-treatment. But that risk is well worth taking to be able to live to the fullest for the rest of your hopefully long life.)