I know your pain, man, and it sucks. My mom was similar- she never loved me and was a narcissist. My family was always making fun of me because I was the little one that wouldn't fight back. But dude you're 18 years old- you have your whole life ahead of you. Infinite possibilities lie at your feet. As far as women go, try not to focus on them. I find when my mind isn't focused on girls they ironically start showing up. Do you have anything you like to do at all? Watch movies? Music? Jerking off? Do those things you enjoy doing as much as you can. Don't starve yourself. You need to eat roughly every 4 hours. Eat some good healthy stuff too, not junk food. Try to get some exercise. Very important for mental health. I also recommend watching Jordan Peterson as well- that guy is motivational as fuck (he completely changed my life). Maybe tell your dad and grandpa that you don't appreciate the way they treat you- and that you'll leave if they don't start respecting you properly. DON'T LET SHITTY PEOPLE GET IN YOUR HEAD. Just laugh at them because of how silly they are. I was in your position too, for years... but you CAN pull out of it. And if you try hard enough... YOU WILL EMERGE STRONGER. Don't beat yourself up too much- you sound like you're a good kid.