Do I or don't I?

Tomorrow marks the middle of this second last Docetaxel round. Only one to go. I've been through probably the worst week and a half of all the chemo rounds so. Severe bone pain and muscle weakness to the point of not being able to stand for more than a few minutes. I fainted twice through the pain. The positive thing is I only have one round to go (did I mention that?). I now have to think about my mastectomy. My surgeon has strongly recommended that I have the left breast removed as I have DCIS still left in the breast. My dilemma is 'do I have both breasts off or just the left'? One minute I've decided to have them both removed, then I decide that one is enough to go through. I'm told that precancerous cells are hard to detect so what if I have DCIS in the right breast too? This is awful! I can't decide. Have any of you had the same dilemma? How have you handled this? I don't want to get this b........ back and have to go through chemo ever again.