Throat and chest pain while breathing.

I had throat irritation after over-smoking one day and dry cough and found black particles in white phlegm whenever I coughed since last 1 week for which I consulted the general physician and he gave me tuffclav 625 and some more tablets and a cough syrup for 5 days which I finished yesterday. And now my throat irritation is quite less but it's still there and today he asked me to stop the antibiotics now and asked me to use steam while breathing and I was also having upper chest pain and lower neck pain on the left side for which he was not sure what could be exact reason so he suggested me BMD tablet perhaps for calcium. But I still have some little throat irritation/infection so should I stop the antibiotics now and depend totally on steam and cough syrup or should I try mucalite as excess mucus could be the reason or carry on antibiotics for 2-3 days more. What could be the reason for chest pain. I've attached the photo of my throat which was takn 3 days ago. Kindly help please.