Why do I have these plugged ears? ?

About 3 weeks ago, I got a really bad cold that included a stuffy nose, sore throat, and cough. I might've had a fever as well since I had chills. The strange part was that my left ear plugged up and that had never happened to me before. I went to the doctor's and she said that my cold should clear up. She said that it looked like I may have been starting an ear infection though and if symptoms persisted, I should take antibiotics. The next morning I started the antibiotics for 10 days. A few days later my ear unplugged but then my other ear plugged and I was shocked. I don't know if this is normal. My cold took a really long time but it got better. However, I went on my 6 hour flight to jersey and the flight was terrible. My ears kept clogging up and it sounded like a vacuum just sucking shut multiple times. It was painful and I couldn't hear. When I got out of my flight I was fine. But now, I'm starting to feel a slight stuffy nose and sore throat again and my right ear has been plugged up for days now. I don't know what's wrong and it's really annoying. Shouldn't the antibiotics have worked? Will this ever go away? Please help!