Hello, Water behind the ear drum could be possible , water inside your cheeks could be sinus infection which is causing problem in ear. Ear and nose are connected through a tube and so the problem has aroused. You need to take decongestant tablets and drops. by natural way if you wish to clear it up then -- You should not blow heavily and specially after closing your nose. Secondly go for a walk daily morning and evening as it will cause more of adrenaline secretion and which is a natural decongestant. It will take around 2 weeks to get clear up. In doubt do reply.