Hey mate, greetings from Germany.
Good Job at taking the first job, this will not be an easy journey but you acknowledged you're addiction and try to move on - that's great. I know the feeling of missing out and I am also stuck at the computer (I am an artist). Deciding to seperate play from work was an important step for me when I deinstalled everything from the computer.
The feeling of missing out and regret is some of the worst there is. Don't try to beat yourself up but also look into the future. It is easy to suffer the pain of discipline than the one of regret for sure. But I also want to say - I did parties, drugs, travel and stuff as well when i was "young" (i am 33 now) and know I lean towards a bit more honest to the "Nerd" Side of life. I play Magic as well, love fantasy movies, games etc - its ok we are in 2020 don't try to be someone you are not.
Could you manage to find some goals for yourself? By the way lot of psychologist suggest not picking goals (which can be failed - starting the cycle of feeling bad about yourself) but rather improve your life from day to day on the actions you take (like drawing, going to the gym etc) So start building strong habits instead of saying "I am going to loose 20 kg of weight in 3 months"*
Good luck on your journey, hit me up when you are in doubt, we can also talk german.