So on the holidays I got just the common flu, and from that I developed tonsillitis, so I went to the doctor and he prescribed me penicillin 500mg and I had to take 4 tablets everyday for 10 days, taking the antibiotics got rid of my sore throats front he tonsillitis. However I was left with a runny nose and symptoms from the flu, fast forward about a week I managed to get rid of all of the flu symptoms except I was feeling a bit drained, and then 2 days later o have a the flu again but worse now i have a chesty cough too. So what I want to know is if there is any reason I keep getting sick?