my son nearly 4 years old, he cought cold when he was 3 months old , I took him to the doctor who given him anti-biotic since that time his immunity becomes weak, because every month I must take him to the doctor due to high fever his temperture gets, high as 40 degrees celsius, the doctors has given him 3 or 4 kinds of antibiotics like klacid 3 or 4 times Augmentine 2 times Zennat 2 times Suprax 3 times , once he got temperature s spasm [ convulsion] ,his appetite to food is weak, he is skinny, I am really worry about my son, What shall I do next ?