Breast reduction questions and worried?

I have just turnes 18 and my right breast is a FF cup and my left breast is a C cup so im having a breast reduction to even them out and also a lift. I have had general anesetic before for something else, but im worried about the scarring. And the pain afterwards. I have no idea what to expect to be honest. Also i need a front fastening, seamless, post operative/sports bra, but its very hard to tell whay size to get??? Am i going to be really swollen after? Im excited but really worried and nervous too :/