What Causes The Feeling Of Knot In Throat Along With Burping?

Hi, i caught a bad cough and cold this week, today is my last of 5 days of antibiotics. I thought I was doing better but this morning I had a very violent coughing episode where I couldn't stop coughing for almost a minute I think. The cough went away with cough suppressant and didn't came back as bad but since then I have the feeling of having a knot on my throat and I burp continuously after swallowing saliva or drinking. Also, my cough that was very dry at the beginning and got better with the antibiotics is now again pretty dry even if I've been taking an expectorant for a week. I'm worried something might be going on. Thank you!