Why don't you just go to university? That is the easiest way to become independent because you can stay in student accommodation. You certainly don't need A levels, lots of universities offer degrees with foundation years (foundation years are a one-year pre-degree course for people without high school qualifications).
I am so sorry that this is happening to you and I'm glad you had found this website to find help. Yes, you can certainly go to college. You have more than enough GCSEs needed since the standard here is 5 GCSEs A*-C which you do already have. It would have been a lot more of a hassle if you didn't so I'm thanking God you do. To add to that, because you are 18 it will be free for you to attend college unless you begin college officially at 19, it's then fees come into the equation however even then it considered whether or not you work so please do not worry about that. What are you interested in studying at university? In all honesty, I think you should leave your uncle's job and find a proper, part-time job where you will be fairly paid but that will also give you time to study. I've never been in this situation before so I can't give a thorough answer however the responses here so far are phenomenal. I can assure you everything will be ok. I have you in my prayers <3
Not certain but if you are 18 and at the risk of becoming homeless then go to your local council, see if they can get you a flat somewhere.
worth a try
OP do you have a British passport, or IDLR in your own right ?