While the side effects of treatment can be both immediate and insidious, I dragged myself through it. Twice. For the most part it was mildly horrible but bearable. Time passes and I'm still here.
You have a tough decision to make and there will be significant pressure from other people who want to influence what you do. It was that pressure that ultimately pushed me into the second round of treatment. That, and the toss of a coin.
I'm still not sure what I would have done if it had been purely my own business, but we live in a society where others really do feel they have a right to an opinion. For better or for worse. Some can be quickly dismissed but some are quite persistent, generally because they fell very invested in us.
Follow your heart, but be mindful you are not in this on your own and be prepared for some opposition if you decide you will accept some elements but not others. I sometimes wish I hadn't discussed my options with some people--it would have been easier not to :)