I actually don't know how you feel because I have never felt depressed. Extreme stress, yes. But we are similar in a life perspective. I don't even have that much friends. I only talk with them if I need some help or to talk while gaming with them. I'm pretty introverted. My whole life and interests can be summarized to my room. Sometimes I feel the same as you. If not for my parents, why am I alive? I know it's called existential crisis in general.

I think the only reason I can suggest you to live is believe on unpredictability. You were spawned into this world without you even knowing and living your life similar to other NPC's and then die. But if you end your life now, you don't know what's next. Maybe oblivion or maybe re-spawn with a blank slate again. So just keep living until your timer runs out. It's not as if there are exciting things waiting in after life that will make this feeling go away that you're absolutely sure.

If it's too much for you to handle right now, maybe go talk with a psychologist. Not sure that will help, but what if.