Go walk/move like a slug around outside and take in nature. Realize how big it is. The grand scale of the cosmos. The ever present incredibly depth of interplay between ecosystems. Realize just how small everything is and that everything will be alright with it no matter what happens to you. Then realize you can channel that feeling into motivating yourself. Life goes on. When death comes knocking you just have to keep moving and keep the other person's memories alive by your own actions. You can say they will be with you in spirit. Either literally in Religion or just through your memories of them. It will be bittersweet but action is the only way to get over such things.
Sometimes you need self validation and video games cannot give you a true helping of that. Just pale imitation. Go out in the world and experience it. Jamming with some strangers might help. Go to a music instrument shop and just browse around. If it is a cool one they will let you play their instruments. Maybe talk to the people in their about music and in time open up about what is bothering you through music. Write a song or even notes that in some way describe how you feel.
I am correct in assuming someone close to you passed away right?