My hearing has a bit of a problem. Please answer if you can!?

Let me start off by stating the I'm a 16 year old male. Recently I was fighting the flu that seems to be spreading in my city in California. Around a week and a half of having the flu, I woke up in the morning and my left ear ached and it felt like there was something stuffy in there. I informed my mother and she said it was a ear infection, so we used a home remedy of warming up garlic, placing it in a cotton ball and placing it in my ear. It worked, the ache went away but me ear kept feeling stuffy, clogged up. When I told her this she told me to take penicillin, which I did and it seemed to have worked since my ear does not feel clogged up. But here's the problem. On my left ear where the infection was, the sound pitches are flat. They're lower pitched and when it comes listening to music or what ever the case may be, it sounds disgusting. If I cover the left ear, allowing no sound to enter, everything sounds normal, thanks to my right ear. If I cover my right ear, the left sounds lower pitched and flat, which is extremely irritating! This may not be major, but its a problem that I wish to be solved. If you know anything or have any recommendations please let me know! Thanks for your time, and enjoy your Holidays!