For what it's worth, I can relate Vector.
One of the ways I've found it gets to you is the expectations we were given don't pan out in reality. We were supposed to be having this great future and people not only don't seem to give a shit but often actively are just mean.
One of the only ways I've found that helps is to pick a goal, imagine being great at it and figure it out to beome great at it. It's far from perfect and works best/on hobbies, but it's something.
I find the motivation issue is a problem with that god aweful question, "why?" combined with past disappointment. The haters have misused the hell out of the question "Why?" It used to propell humanity foreward. Now it destroys motivation and motion, becuase they've made everything "lame." People also get upset with me for moving and talking fast, and I think it is because it makes them look bad (doesn't matter if I'm helping them or not). They expect this behavoir of a stupid detached 90s movie shithead who is too good to give a fuk about anything. They destroy everything with, "so what?" Reently it has been at this point where I get atively mean as all hell because that motivation killing she is them trying to drag me down to their level.
Be excited about something, no matter what it is. A TV show, a game, drawing, whatever, and do it. It is so fucking hard and I know it. You are a great person.....