I often get pain in the right ear. When my acid level gets a little too high and my sinuses react by creating a little extra fluid, it seems to put pressure on my right ear, like an ear ache type feeling. This seems to happen most often during the night.
Sometimes it helps to flush out my sinuses with a netti pot in the morning. I'm not sure what that's doing to help. Either it's loosening up some kind of blockage or else it's flushing out the traces of acid.
Probably you get the pain in your left ear due to some minor asymmetry of your sinuses, or maybe it has to do with which side of your body you spend the most time sleeping on.
As long as you keep your sense of humor, you'll be fine.