What Causes Vaginal Dryness With Buttock And Bowel Movement Pain?

Starting 2 days ago, I've developed vaginal dryness. For almost a week now, my butthole has been very sensitive (at first itchy..now slightly painful) and starting tonight it hurt to go the bathroom. Also tonight, it hurt to pee for the first time. Last week I had strep and was put on a full course of antibiotics, which I finished yesterday. I was also given probiotics. On Monday, I made a pretty drastic change to my diet/exercise routine (for the better - eating healthier like more yogurt, fruit and I worked out 3/4 past days). These have been the only changes in my life.. so I'm wondering if either one could be responsible. Thanks for any help.