I quit wow all the time for 6-12 months before coming back. People that play 4 years without ever taking a break are hopeless addicts.

Also, why play 15.5 hours a day? I don't care what you do, if you do it 15.5 hours a day you will hate it. WoW is not a job, its a game to enjoy, if you're not enjoying it don't play it. Come back after your brain tells you you actually want to play it again

I only get to play a couple hours a day, sometimes none for 2-3 days at a time, so its hard to get burnt out.