Whenever I take a shower or bath lately my chest/throat get really tight and it feels like I can't breathe. Lots of coughing. Obviously I'm able to breathe enough to not pass out etc., but my chest just feels unbearably tight. Tonight was the worst it's been so I'm a little worried. I've never had asthma, it doesn't happen during runs or anything, just in my bathtub. I feel fine now. Any idea what could be causing this?