So I Noticed That My Ears Were Being Weird Last

So I noticed that my ears were being weird last weekend... then like 3 days later I remember taking a nap and woke up long enough to feel something close or cover up my left ear and now it's really hard to hear out it... I can still hear out of it but it's like a distant sound and I can hear myself talking. My right ear is totally fine now. I went to a doctor on my college campus and he said it was an ear infection. I started amoxicillin yesterday morning and I still have terrible healing in my left ear. How long until it takes for the medicine starts working? Or on another note I'm also afraid I went partially deaf and maybe that's why I can't hear good