Spend more time on foreplay, that can help you get wet. You could be dry because of so much friction going on. Nothing wrong with having that much sex, but also condoms can dry you out at times (at least they do for me. And as a side note, I really hope you are using condoms because of being on the antibiotics if you weren't informed that it can decrease the effectiveness of BC)
Also it'll depend on how you're washing too, if any soap is getting INSIDE your vagina, it will mess with the PH balance and dry it out.
Best bet, is either give it a break for a bit, let your vagina rest, and body replenish fluids(being dehydrated may be a factor as well) then see what happens. Or invest in a lubrication. (something from the grocery store, or if you're old enough, go to an adult store and get some that will be a higher quality)
Hello, you need to slow down, sex is not an every two miniute thing. I would tell him to finger you. If you are on the pill, tell him to dip is finger in water. This will got you a little wet. Hope I helped!(: