Are you sure this is the right place to express yourself just because this site name is Hidden Answers?
Personally, I don't think you'll find anything that would definitely fix all your problem here. Don't ever expect you'll find a wise-monk-like digital friend that will give you advice on anything in the realm of internet, either this site or the other. Don't expect anything beneficial from it.
What should you do? Who cares about that? Who cares about your life problem? People here in Tor already sick and have tons of problem, mostly mentally. So welcome to the world of sick people. You may be one of those who thought the only way left for you to express yourself is not in the surface no more, but in the underworld. Society doesn't give a f*ck about you, so all left... the dark side? Nah, just some people that can't fulfill most of the society standards.
Advice? Go outside. Touch grass. Enjoy the sunlight and the sunset. Go farawaay to a place where there are no one to disturb you. Suicide? That's an option, but you're an atheist, so where do you think you'll go after you die? Maybe you'll just repeating life again and suffering the same sh!t? Lol, just don't.
I know this is long sh!t, and reading this your eye would probably suffer, but maybe I just can't bear people like you.
Save yourself money. If there's a chance to go outside, then go and make yourself a passport. Go to a country where you can start you life again with a new identity.
What about you health? Stop using computers dumbass, if you're that addicted, then try to limit yourself a few hours day by day increasing that hour limit, if you're bored, then do something productive, idk, drawing, writing? Anything that could distracts you for a moment away from the screen. If that's not an option, go outside, run, exercise. Not also an option? Then exercise in your room, make yourself sweat, so when you sleep, you can have a goodnight sleep since you're tired of the exercises. Read books, gain yourself skills.
About your sh1tty family? Don't give a f*ck bout them. Just tell them that after spending years in front of your computer a mythical digital djinn just blessed you, he told you that by staring at the computer, it's the same as doing salat. If you're mother and sisters are muslims but they still believe in witchcraft, they would probably believe you lol. Jk jk.
You have the life, you have the option to what to do with your life. So does the others, if they have the option to mock you and say the negative things about you, you also have the option to defend yourself. But don't kill them, that'll only suffer their physical form. Just prove to them that they're wrong. About every negative thing they said about you, prove them wrong, and they'll suffer from embarassment for the rest of their life. You're a saint? Forgive them, that'd suffer them more.
You don't need to marry a Muslim woman, you can ignore those voices, you can learn and use your common sense, you can ignore those invisible people and try to have a light conversation with people, that other people can see too, if that's not a possible thing yet, talk with a cat or bird :3.
Bring yourself a motivation. Remind yourself of your past dreams, and things you already achieved in your life, gather all the experiences, to level yourself up, Use that experience to escape your situation. Get it together man, and win this life. It's not over yet.
And as a theist myself, I'd say, that God is real man, it's just not all people could feel it nor want to feel it, and we ourselves that tends to abandon him instead of the reverse that most people believe.
Hope this helps... Again, I can't bear people like you.