Normal my chemo dose was reduced massively. It was an infusion and tablets but for cycles 2, 3 and possibly 4, I can't remember
I just had the tablets, at a reduced dose. Then they reintroduced the infusion I think at half the original dose but he said we could go lower if needs be. He was quite concerned that he would kill me and the effect this would have on his career 
I think my dose was calculated on weight, which they use with height to estimate your surface area. But I'm extraordinarily dense
so my weight gives a much higher surface area than I actually have. That's a medical opinion, not just me making excuses 
I hope your mouth feels better soon and that you're able to regain some weight!
mrs good luck telling DD2, I'm sure she will understand why you've waited and hopefully DD1 can support her.