Hmmmm. You said you don't receive support from your family. But family is not necessarily blood bound. Your friends and your partner are much more your family than the ones who brought you into this mess. Nobody owes their parents anything. They chose to give birth. And if they don't support you and give you the means to improve and get better, then rely on those you trust.
About school. It's horrible. It's demanding in a way that makes no sense. Unfortunately it's a means to an end, a job. There are many jobs that don't require diplomas and pay good, though. (
https://www.indeed.com/career-advice/finding-a-job/no-high-school-diploma-jobs) this link seems to offer some ideas. Unless you have a goal of becoming a lawyer, doctor, engineer or something that requires higher education. Then you'll have to play the game until you succeed. Please note the "higher" in higher education does not make those who go through it better than anyone.
Society builds the norm that for you to be successful you have to be rich or powerful. But that is very far from the truth. Being successful is an interpretation of your goals. If you want power, then strive for it. But if for you, being successful is having a loving family, a comfortable life and doing what makes you feel good, then it can go the absolute opposite way.
See, CTB can always be a last choice, but I see you want to improve and you want to get better. I know that when we are in that shitty low self esteem spree it seems we don't have any habilities, but that is far from the truth. Everyone has something they are good at. And for that, the educational system we live in is absolute dogshit, because it only wants to breed mediocre people to do grunt work and get paid ridiculous wages so they have to live check by check and be absolutely dependant on the exploitation they are submitted to everyday. And those who came from rich families or a very few that learn how to play the game, may get one of those supposed "prestigious" jobs in corporate, or law firms or hospitals.
I say this to you now. I am a doctor today in my country. I've worked all my life for this. Tried to take my life for this as well. Fortunately, I failed. And I see the absolute majority of doctors as unhappy, unresolved and miserable as I once was, but they don't face their issues, and they build up and they end up miserable, resentful and bad doctors that treat patients like shit. You have to find what you love. There is a market for it.
Feeling afraid is absolutely normal. When you try and look at the future, and what people expect of you, it may seem overwhelming. But if I've learned something in my short span in this mess we call world, is that whoever tries to achieve power for power's sake, or money for money's sake, end up consuming themselves, turning crooked and corrupted.
People that work with their natural habilities, that do something they enjoy doing and feel good, naturally feel fulfilled. I'm not saying life will be a stroll down a cherry lane. It's fucking hard. You have to pay bills, buy food, pay rent/mortgage. There is self doubt and fear sometimes. But as you age, as you face the challenges and burst through them, you'll be ever wiser and stronger. And one day, you may pass your knowledge on.
Don't think about the far future if you don't want. Rely on your family (the ones that support you) and feel their love for you. Discover your purpose, your abilities. Have fun!
Just an FYI, doing drugs or chugging massive amounts of alcohol are not an ability.
I'm here if you want to talk.