Hang in there it will come...if it was easy everyone would do it and is why we call it hunting not killing...
One can sit forever but it most likely wont do any good if wind is wrong, if your set up is wrong and you are skylined or stand out oviously and/or one is fidgety and moves a lot as mentioned above...
If its been five years with no shot something is wrong...
Find that funnel between feeding and bedding areas, and watch the wind which is very important...
Try a ladder stand..watch wind and being sky lined..provide back cover in stand...scent is better dissapated in stand but still is a factor...practise shooting from stand...
where is their water source...another good place to set up...they have to have water twice a day at least...
They have to bed mid day to process and digest food...
Early morning and late evening they will feed and water
Above is most effective early and pre-rut
During rut all bets are off and may be harder to pattern
couple factors to ponder...
Neil