HELP!! i hold a unacceptable immune system?

i get sick every month or every other month and it get worse each time
how can i be paid it stronger? i am not overweight, do not smoke etc etc
please help :(( Taking 1 or 2 gm of vitamin C every light of day will boost your immune system.
Taking 6 high strength fragrance-free 3,000 mg garlic oil capsule every day also help. Garlic is very honest for people near sinus problems. It is both an antbacterial agent and an antimicrobial agent.
eat more fruits and vegies drink more sea, that will help alot, and try to excercise possibly that will help remove toxins?