Im shaky for 2 days, just getting over sinus infec. & cold have had diarrhea for 7days now. had iv fluid last saturday. what keeps causing this?

Systemic infection?: If you need IV fluid, you likely have had very severe diarrhea. You may be shaky if you have not taken in much food and you may also have shakes if you have a systemic infection (i would expect that you have a fever however). You need to talk to your doctor about this asap.

Dehydration: Your physician should be consulted. Even though you say you were given an IV fluid it may not have been enough to correct the problem. Drink more water and see your family physician to also correct any electrolyte values that may have been affected by your sinus infection.