What Causes Mild Pain In My Left Ear?

Hi, I visited the doctor yesterday as I've had mild pain on and off for around 4 weeks in my left ear. It has recently moved to both ears. The doctor said that my eardrums are both being pulled inwards and that the fluid behind them is now like a gel? There is no chronic infection. She has told me to use steam and to pop my ears. I have tried this many times times but they wont pop she I use excess force?