Anybody who plays an inordinate amount of video games is at the very least depressed on some level, whether they can acknowledge it or not. Of course there could be other factors involved, like living in the middle of nowhere, being disabled, etc... but the fact remains that heavy, chronic gamers almost invariably experience depression. This leads us to a 'chicken or the egg' scenario though - Do gamers play a lot because they are depressed, or does gaming a lot make one depressed? I suspect it's a bit of both, with the former being more influential by far.
Myself included, I have never known anyone in my life who is a hardcore gamer who IS NOT depressed. That's anecdotal but still counts for something. Furthermore, 12 hours of play time per day is far beyond what most heavy gamers even play. That's an attempt to escape your life. Your problems. Your feelings. It's basically a drug, and definitely an addiction of a sort.
Regardless of your copypasta definition of the world "problem," you know exactly what I meant because I spoke in plain colloquial language, so don't equivocate here. Gaming 12 hours a day is a major problem whether or not you have kids or are in a relationship. It's bad for YOU as a person physically and psychologically. Once in a while a 12 hour marathon isn't a bad thing but every day for a month straight? That's a red flag, a serious red flag.
Between gaming and sleeping you had a total of MAYBE 6 hours per day to do everything else you need to do in life... cook, eat, shop, socialize, bathe, clean, handle personal business, look for a job, keep in contact with friends and family, and any number of things that don't involve gaming. I think it is safe to assume that you were quite likely not attending to things that you needed to attend to and probably sitting around your abode all stinky and unkempt.
Anyway I hope that you're not still gaming 12 hours a day or anywhere even close to that... for your own sake. Seriously.