School, math failing, summerschool, Stress! Help me plz!?

In 8th grade I was in algebra. I didn't know how to do the stuff but I would always guess on my homework & would get credit on it but would fail on tests. I passed the class with an A but not the final test. I had to retake it In 9th grade. I did all my hw but failed tests. I failed both semesters. Now I'm in summer school for algebra 1a & 1b. It's 1 month long. Theirs one week left & I checked my grades & have D & F.....! I seriously try so hard but I don't get it. I have so much stress! It's killing me. I cry everyday that i can't pass. I do all my hw & use the example on the book to help me solve them. Then when my teacher checks HW, he doesn't give me full credit cuz the answers are wrong! I used the examples & I still get it wrong. Plz some1 help me!