Suggest Treatment For Ear Problem

I am 27 years old, male, 5'7" and 75kgs. Since age 5 I have had ongoing ear problems in my left ear and over the years have had my adenoids removed and 5 or 6 grommets inserted. The last grommet came out June/July 2008. I didn't issues until Christmas 2010 where I got an ear infection after swimming. Since then the problem hasn't fully corrected and I still have regular but intermittent pain, generally when my blood pressure is up (i.e. exercising) or on hot days. My ear cracks and pops when I blow my nose and there is pain and a vacuum sensation if I block my ear. When I had grommets in the past I used to block my ear with swimmers putty to go swimming, but now the pain when I block my ear and the vacuum caused hurts too much. However flying is not a problem, which I find odd. The local GP recently told me there is some healing tissue at the top of my ear drum but couldn't see any other reason for my problem. I have an appointment with an ENT but not until February and I am hoping there are some other options or reasons as to why the pressure is building like it is.