I don't know if I can say anything to change how you feel or how you think, but I do know that I have experience being where you are and I do know that everyone deserves to find happiness. Maybe I won't hit on every point of your post but I want to address a few things.
First off, life sucks. It's not fair, it's not always happy, and it can just be terrible. For everyone. And in 100 years from now, nothing we lived through or did or accomplished is going to have much importance. 100 billion years from now, the sun explodes, nothing will matter at all. So why live? Why does anyone live?
Because we are alive. Because we wake up in the morning and because we live in the present. And maybe nothing we do will matter a long time from now, but everything we do matters when we do it. We don't live to die, even if you view death as the end all. We live to love, to laugh, to cry, to hurt, to believe, to fail, to reminisce, to doubt, to succeed, to try, and to hope. I know it sounds cliche and seems like it's so illogical but life cannot be explained just by biology, you cannot define human emotions and human connections with neurotransmitters and sociological preferences alone.
So maybe I'm not making sense. What I'm saying is it's ok to be depressed and it's ok to not be ok. And it is so good that you are staying alive for the sake of those who love you. But if there is even the smallest chance you could stay alive because YOU wanted to be alive, cling to that feeling and fight for it because it's worth it.
School sucks, and it doesn't always seem practical to spend countless hours stressing yourself out just for a slip of paper that tells you that you passed or that you can work specific jobs. But in our world, it's almost necessary. That doesn't mean it has to control your life though. Do your work if you can, but first and foremost, make time for yourself. Expand your interests, focus on hobbies, do something fun. Live.
Finally, relationships. You love your family and they love you right? Do you ever just step back and notice how special and weird and crazy and complicated these kinds of relationships are? You have people you can fight with, but always make up. People you can hate but love at the same time. People that make you feel special but could tear you apart with a few words. And in the end, people you know will be there for you. Spend time with them. Right now, they are your reason for living so embrace it. Don't shrug off this gift because it won't matter in a long time, cherish it because it doesn't last forever. That's what makes it so special.
I don't know if you read this whole thing. I don't know if I'm a babbling idiot that just makes things worse. What I do know is that you deserve to be happy and death is not a solution. Live for now. Because people care about you. And maybe you think your dad doesn't but maybe you think wrong. So do the hard thing and talk about it: With him, or with others that you trust. And one last thing, the fear of not being able to love a child unconditionally because of who that child might be is a common one. Some people just don't want to have children and that's respectable, but in my opinion, I feel like there's something about holding that fragile human life that you created in your hands that makes that love unconditional no matter what. Knowing they aren't perfect, but they can be perfectly flawed because they are yours.
please please please comment if anything I said is a misjudgment on my part or if anything I said is offbeat