Every Two Months Or So I Become Ill. So Weak

Every two months or so I become ill. So weak that I cannot function. Meaning I miss work and normal activities. I have been to the Dr. and told I have a virus, it will have to run its course several times. I have taken anti biotics with no results. I have no fever, sometimes diarrhea but not all the time. All I can do is sleep and lay around. I try to push through the weakness but I just can't. By day 10 I am better, energy returns and back to normal. This happens so frequently that I am afraid something else is wrong and I have no way to make myself understood. My email is YYYY@YYYY . Thank you.