It looks like you're still holding on to your romantized version of your life @13 while not realizing what's around you. Because come on now, your ex gf when you were 13 isn't something you know should be dramatic about. Not only its been a while but you were a kid back then, now you are older, stronger, wiser, a bit more mature.
You know how I know that? Cause you've got the brains to realize something is not right in your life. You realize you're capable of more. You have the guts to post this in the Internet despite the trolls and the people that WILL look than on you for looking advice. Fuck them, there's nothing wrong in wanting to improve your life.
You recognize the game is a problem which fucked shit up. Well cut. The. Game. Seriously. Now that you have stopped dumping 6hrs a day on a skill it won't benefit you irl, what to do with the time? I believe there are three pillars to well beign.
Health pillar. Go outside and hit the gym/excersice. When you work out your brain segregates some hormones that are proven to pick up your self esteem. Not only that but making you more attractive will help your morale. You are on your twenties? Your body is in its prime. NEVER in life your body will feel better. So do yourself a favor and treat it well. Health pillar. Never forget.
Social pillar. You lost your friends due to something, so I think you are in the back foot with this one. Go outside and expose yourself to people. You play the guitar? Go get some classes and meet your fellow alumni/teacher. Try to make a band, try to connect. Studying in uni? (you should) go and socialize with your fellow students. Yes some people are pricks but it's a matter of time till you find people who are likely to become your friends. Socialize my dude.
Success pillar. What's your goal in life? What do you want to do for a living? Now think about this. How much time do you dedicate daily to achieving that goal? My guess is 0. Do you even have a goal in life? If you don't then you could figure that out. By giving yourself a direction you can steer your life as you please through the good paths of life. Yea everything won't be sun shines and rainbows, but if you are convinced that's what you want, go get it. Now hold on. There's a reality around you. You can't just wish to be Americas next top model. Adapt you dreams to your reality and opportunities and strive to make the best of you. Your end game goal should be something tangible, something that maybe real. You cant just wish to be a pro dota player and be 2k. Sorry it doesn't work that way, if you have been playing since you were 13 and are not pro by this time, then odds are you won't make it. But that's okay. Adapt your life goals to your reality box. Once your reality changes your goals should too. It's a circle that it feeds on its own. Each iteration will fill you with gratification, making you a successful guy.
One last thing. Read. There's a shit ton of literature. Everything you feel someone must've felt it and wrote a book about it. Read. It will make you wiser.
Fuerza y mucha suerte.