[PSY]

I'm not sure how social services works in London, but I imagine you could call the police/child services and explain that your caretaker (aka your mother) is addicted to alcohol, to the point where she is neglectful in her duties as a caretaker. Definitely mention the recent incident where she left the gas on. Your mother may not be abusing you now, but she certainly has reached a point where she's not looking out for your best interests... and you may be able to do something about your situation if you can prove that to the proper authorities. She could be forced to attend AA meetings, or you could be removed from her home until she gets her act together, or there may be other options that the police/child services can offer.