I started gaming 38 years ago. This is something I understand well. It snuck up on me over decades but looking back I can say that my gaming addiction was a huge contributor to all my problems. I'm exactly like you, I can't play in moderation. I got nearly straight As in college my first year and almost flunked out by my third because of it. Took a year off, quit cold turkey, went back and was back to my old grades. It wasn't WoW, but it doesn't matter, it's the same. Many games these days, especially those like WoW that profit from increased player engagement time, are carefully designed to be addictive by selectively activating the dopamine reward centers in the brain, and for people like us it is a major problem.
Either it's nothing or it's 8 hours a day (while also working) or 12-16 hours a day (not working). I've called in sick and even no showed at work once because of it. The last time I went cold turkey I started sleeping better, I ate healthier, started a running regimen and going to the gym, lost 60 pounds, started doing much better at work and started a new relationship. After I got sucked back in, my relationships at work and with my ex became so strained that I eventually lost everything because I couldn't bear how hostile she had become even though she had no idea I was gaming (I wasn't fun to be around either).
I think people who focus on violence and the content of games have it completely wrong. The real negative impact is in the isolation (interaction in games is great but it isn't a real relationship and doesn't carry the associated benefits), lack of sleep, lack of exercise, lack of socialization, and what all of that does to your brain over time. Sleep deprivation in particular has a high correlation with depression and I personally believe after what I've experienced that it may even be causative when it becomes chronic. It's all a perfect recipe for creating and worsening depression into a nightmare beast like the one I have now.
People who can moderate their behavior don't understand what it's like to be that addicted. What's really insidious is that from day to day you can't always even tell how much of an impact is has on you. Only looking back over years and decades I can say that it definitely changed the course of my life for the worse, and while I sympathize with the intent of the idea "what's the harm" for people like us it is actually quite devastating.
One of the things I found difficult about quitting was that suddenly I just had so much TIME. I didn't even know how to fill all the hours and that's eventually what dragged me back in. I wish I could have just learned to play the violin or something, but after I lost it all I went right back to it. The dopamine rush from playing numbs all the pain but it also ensures that I will never recover.
If I was better socially and didn't have that struggle in my life I think I would have successfully quit and stayed away because real life would be so much better that way, but I couldn't do it. The longer you wait to quit the harder it becomes because you no longer have the social experience that your peers do, and so you become more and more alienated socially. One day you wake up and you're 35 and you've never been on a serious date, and at that point course correcting becomes a much bigger challenge.
If you want to give it up my advice is to do cardio every day, stop eating junk and substitute as many vegetables as possible, force yourself to be social and try really hard to cultivate enough hobbies to fill your day. It's so fucking hard at first but after about a month it becomes easier when you realize how much better you feel. It's much harder to quit than to stay away, at least it was for me.
I relapsed so hard after my losses that I don't personally have the will to do it anymore but maybe you will. Also if you're indoors all the time, you might consider having your doc check your vitamin D at your next physical. I have a chronic deficiency because I spend so much time indoors, and recent research has shown that vitamin D deficiency may be correlated with depression. When I was in recovery I took both D and omega 3s, both which are supported by research indicating deficiencies contribute to depression, and really noticed a difference.
Good luck either way, I wouldn't wish my life on anyone. I hope this was at least somewhat helpful to you.