I'm a failure and I can't do this anymore

I'm a junior in high school doing AP Physics. Last semester i was doing great and got an A in the class. But this semester is killing me. I've given up all hope for getting an A (I've only got 7 more tests and I would have to get a 100 on all of them or get a 5 on the ap exam). In fact Im praying i at least get a B. For context I did rlly bad on my tests and now my grade is a 69 (Funny number ik). On my first test i got an 83. And i got a 50 on my next two tests. So my grade is super low right now. Luckily i can raise my 50s to a 60 with test corrections so my grade will prob go up to a low C. Also these scores are curved and there's a massive curve so my real scores were much worse. I just don't know what's wrong with me. I was doing fine before. And then i come back from break and suddenly I can't do physics anymore. I feel like a massive failure. I goofed off studying for the first two tests. But i rlly tried on the momentum one but still got a 60. My friends used to say i was good at ohysics and stuff but now I feel like a fraud. How do I do better?