My basketball mentality..?

I'm a jr playing on varsity for high school in basketball. I like basketball but I'm intimdated. I used to have amazing potentiaI but i was cheated by a coach for 3 yrs who degraded me and this is the first time in such a long time to play with more confidence. ( we got a new coach) it hurts to know what I coulda been..shoulda been.. Since I'm behind in bball. But all I want to do is to be able to play well and hard. I know I have that potential but I don't know how to unleash it. I feel like I've been programmd to play differently cos of my rough road. How can I reinstall my skills and be mentally tough