Transferring High Schools?

I am currently a sophomore at a private all girls catholic school. I went to public school all my life up until freshmen year. I have liked most of my time here, i have met really nice people and i love the environment/atmosphere, but I’m seriously thinking of transferring to my public school. My grades are HORRIBLE. i thought at first it was just because i was transitioning but no, my whole entire time here my grades are horrible. my gpa is like a 2.2 and i want to be successful and go to a great college, i think staying here would not make that happen. I have talked to my guidance consulor many times and have tried to get a tutor but there is always a problem with finding me one. Last year i failed biology and alegebra 1, i could;ve done summer school but i would have to pay almost 500 dollars for both classes and my parents cannot afford that. I also feel bad for making my parents pay almost 20 k a year. My public school is pretty good for a public school and i think i could really excel there, but I don’t know. If anyone has gone through this or can help me out at all it would be really helpful and appreciated!