Get the F**k away from my "family" or don't change schools please, learn to get independent from that age (I'd be 13 then), never trust that guy who would become your best friend. And demand the thing you need the most from the person who can make sure you get it

To be fair, time is weird thing, I am what I am due to circumstances that happened throughout my life, an advice might change it for better or worse like flipping a coin, each day has been a product of my (dumb) choices and circumstances, knowing more may help me make better choice, but knowing universe, it might as well end up fucking me over regardless to keep things perfectly balanced.