Suggest Remedy For Side Effects Of Taking Penicillin

Hi, I have just come back from a 6 month overseas trip in India and fell really ill 3 months ago. I had a fever/flu and vomiting for 24 hours. I was out like a lightbulb. After that I believe my immune system was comprised and I began to have chronic coughing and phelgm. I took cough medicine and did not find relief. I was advised (not by a doctor) to buy some pencilin as it's readily available withougt a prescription in India. So I did withouth thinking and after that I have had numerous complications with my skin and body.