100% of your issues, lie in this sentence.
Are you afraid?
Have you found comfort in your "place" or your "lot in life"?
Do you find it easier to just do the things you loath about yourself, and almost enjoy loathing yourself?
(If any of those answers are "yes" you should check with a competent doctor that you aren't depressed, btw.)
If those answers are a resounding no, then you just need to get going and it will snow ball. Personally I got a lot of motivation by beating people, being better than them, or otherwise just being a better person. But I'm sort of a competitive guy, so... I'd pick someone I hated (like my father at your age) and would do absolutely everything in my power to be a bigger, better, stronger, faster, smarter, richer man than he was... That alone got me through school, a damn good career and a sweet wife and kids...
If you aren't competitive, do it for the pussy. As shallow as that sounds, it works. I mean, doing it for yourself doesn't seem to have the gruff to kick you in the ass hard enough to get up off it, so maybe do it for the chicks man. Read more, diversify your interests, know enough "celebrity gossip" to not be a social outcast, but be above that fucking drivel.
Whatever you do, find something, an idea, a hobby, whatever, can be big or small, latch on to it, and get fucking good at it. (Preferable it is a social hobby and not Xbox, where you sit in your room all night.) Then lower your standards and go and try and have some fun.
Be sure your hygiene is on point 110% of the time. Don't nee dot be dressed up all metro, but son you need ot smell good, and look presentable at all times. No skank breath, no "my cloths smell like a locker room" bullshit.
Simple shit like keeping your living space clean and orderly can do wonders for your mental perspective of the world.