Screen won't scroll properly after shower

There are multiple problems that could cause this behaviour, but most likely this will be a problem with your screen (touch part). There are only few shops that replace touch only, because this is not cost effective and labour intensive work, so you will need to replace the full screen assembly.

Another tip I would give when you bring it to a repair store; Tell them the phone could contain water damage. The screen most likely got damaged because water got in (even though it is a small amount, in the form of water vapour). This could also effect other parts of the phone in the long term. The store will most likely treat the phone chemically to make sure all the water is removed and that it cannot damage the phone further in the future.