Getting braces off soonish?

Hey,

My ortho hinted that sometime soon I might be getting my braces off, and he has placed power-chains to close the gaps. Anyway, I am so freaked out that when I get them off, I might have brown marks, or my enamel has worn away leaving white marks. I drink lots of fizzy drinks, and the first time after I had my braces tightened, I could hardly put the toothbrush on my teeth, let alone brush them properly as I would end up crying from the pain. So I have some questions.

1) If I did get brown marks, could I get my teeth bleached?
2) If I did get the white marks, would an enamel restoration toothpaste help and what would happen if this did happen.

Please answer my questions, and I know I was stupid back then with the not brushing my teeth thing. Thanks in advance (: