Sounds like you need to try and distract that HA mind of yours!! I know these are all valid concerns to you, but think about it logically.....with a sinus infection, as long as the weather is windy and junky stuff is blooming, you are going to have sinus issues on some level, and some folks, myself included, deal with sinus nastiness most the summer....
As far as the breast issue, the soreness can take a few days to a week AFTER your period to settle down....please, do not let your mind think of this for more than what it is!
Get out and enjoy yourself today and to heck with those symptoms!!