This usually causes no long-term problems so I wouldn't worry about the eye rub. However, I'd be more concerned regarding the shower and getting tap water in your eyes. Tap water is not sterile and in fact contains fungus and protozoans such as acanthamoeba which can cause serious...
It can take up to 3 months for the vision to stabilize after PRK, sometimes longer. The fact that you saw so well after 20 days is very encouraging. You should see your doctor to make sure that your eye pressure is ok and that everything is healing properly.