Football Games are tough, here is what I did.
At first I told my friends that I was not going to drink for 2 weeks, after which I told them a month after which I told them six months, at a point they stopped asking. Once they get over the initial reaction (remember this is new to them also) they really won't care. After a while you will realize that no one really cares how much you drink or do not drink unless you act like an ass (either sober or drunk).
Football Games; I offer to drive, people are always thankful and it gives me another reason to not drink. Have a plan for the tail-gate, because you will realize that sober the reality of sitting in a parking lot for an hour an half without getting smashed is pretty boring. Bring a football and throw it around, play games, I smoke a cigar, just do something because it will be the toughest part of the day. Once you get through that it is all down hill. Do not bring much cash, beer is expensive at games if you don't have the cash you can't buy the beer. Watch the game, I have more fun now that I can pay attention and remember the games instead of being in the drink line or bathroom.
Do not be too hard on yourself, it will seem that everyone is paying attention to your drinking or lack thereof, they are not!! It just seems that way, give yourself a break and try to be calm and keep thing in perspective, you are there for the Game and to get home safe.
Good luck,