As always, you have to decide what to do. It seems like you have already made the decision to go back, and are looking for support. Whatever you choose, you have my support. But it seems everything now is bad, and everything will be better. I don't know whether that is the truth. The grass simply isn't always greener on the other side, even though it might seem so.
But it would help if you could be more
open, either to friends, family, or anyone. So if moving back to your real family will get you to be more
open, I think that is the choice to make. Education, work, money, a job, they are all important, but only because they are there to make it easier to live a happy life. Happiness is what matters, and if moving back will make you even the slightest bit more happy, it is worth it.
If I recall correctly, you are also 18, and I would love to chat with you sometimes. You can find my email in my profile if you want that, maybe even such a thing as a virtual friend might help
All the best!
Acceptance is the key
The World is but a reflection. Smile, and it will smile back.Try to keep smiling! :)