Summer hols -Can I turn my grades around?

I basically wasted year12, not because I didnt care but the opposite, which lead to me being emotionally unstable and performing poorly through out the year...I am planning to work as hard as I can in the hols to basically learn y12 content rlly well and so be ready for y13...and i need to jump up so much more grades to get to where i want to be ....I want to know is the hols enough to make that change in my grades....and how can I stop thinking of my y12 because i cant stop thinking about how i would probably getting the results i wanted if i had approached y12 right and now i am like am i even smart enough to be able to pull this off? like has anyone else done that in a shirt time frame etc...

Yes you can, but I would not suggest working solidly throughout the 6 week period as you risk burning out. Everyone needs a break to recoup, and the fact that you said you were “emotionally unstable” makes me think that a break is even more important for you. I would say you should have at least 2 weeks off, if you end up studying for the rest.