I’m afraid of bathtubs

I am afraid of bathtubs. I won’t go near a bathroom with a bathtub in it. Whenever I get close to one I get the shivers and grow pale and feel nauseous. I don’t quite understand it though, because, I have one in my bathroom in my room and I can go near that one, no problem. But any other one I freak. My friends don’t understand. I have no idea what to do! I’m only 14, so maybe I’ll grow out of it. I hope I will. :D