How soon should u start to feel relief from a yeast infection when taking fluconazole? day 2 still having horrible burning when i urinate & awhile aft

Maybe not yeast: Normally symptoms would improve by now. If still no better after 3 days, maybe it's something other than a yeast infection. And yeast usually doesn't cause such severe symptoms like you seem to have. This could be a urinary tract infection, or severe allergic or chemical reaction. Maybe herpes if open sores. See your doctor ASAP for further diagnosis and perhaps other treatment. Good luck!