if you starve for levels.. or if you cant take your eyes off your 'xp circle'.. it will seem to take forever
set smaller goals to archive. level up your licence, your alchemy skills. go to high level areas, explore. try making some money. whatever.
just stay the f* away from "omg 6741 orcs to kill to reach the next level"
(im at lv49 + 85-99% for almost a week now, for example. and i still have fun
)
ok, this wasnt really about grinding. for grinding my tip would be not to stay in the same spot. CP for example. no wonder you feel braindead after killing a tousand harkans or ogres. wander around the map, kill different monster, beat up some elites, the xp might be coming slower compared to grinding really hardcore, but its worth it i think