Well, if your aunty lives there she may be able to help..
Normally, it's only direct family members (parents, children) who can get green cards (or the aussie equivalent) for another member of the family to live there, but given your situation things may be different.
If your aunty could become your new legal guardian, or you could request to live with your aunt in order to be close to a relation, then things may flow quicker :3
Tiglet, you may want to contact the UK Embassy to start asking questions about how you could move out there. You should explain your current living situation, and ask what steps you need to take and how long they think the whole process would take. You should definately contact them asap to know where you'll stand