I read somewhere that smoking water bongs too much can damage your lungs because the hot smoke makes some of the water evaporate and then you inhale it with the smoke then after time it builds up and you got water in your lungs.....but I'm toooooo high to remember where I read that and if it was reliable or just some random ass website....but anyway hope your lungs get better, when mine get too shitty I try to take in 3 to 4 times more air than smoke in after my hit to just make it not a such harsh hit