hi. This is bit difficult to say why one gets flu for such a long time. Let us find the possibility of associated other medical problems which might have been shadowed. You need a good clinical examination by a Doctor to find out probable other diagnosis as the treatment would help you regain the energy fast. The probable help : First of all try to take a full bed rest for a few days- Keep mobile off, no meetings , real rest- this will help to recapitulate the energy. Take multivitamins with Ginseng Plenty of oral fluids Fruit juices and start working only once you really feel fit. Work can be continued better with fitness. Otherwise recovery will be really delayed for a long period .