How do i get an A in algebra?

Well, ever since elementary schol math was my best subject and came very easily for me. So I easily got very good grades and usually got A's. Because of that I am one math ahead (I'm in 7th grade a taking 8th grade math and last year I was in 6th grade and took 7th grade math. At first I was struggling with math last year but then after about 2 or 3 tests I got better ang started getting A's like usual. Now I'm in algebra which everyone says is easy but I'm having a lot of troubles!!! : ( I do everything I can i go get help from my teacher during studyhalls, get practice tests, study every night, ask my dad (who is a math professor) questins, abd actually help everyone when we do an activity, and study a ton!!! I still don't do could pretty much get B's and C's on everything : ( I thought it would get better like it did last year but it hasn't. I feel like i work way harder and try way harder than the people who get A's it isn't fair : ( My parents say it's because I'm nervous but I'm actually very confident when i take a test and do every problem over again.Math used to come so easily to me, and i wish it would still be the same. Do you have any tips!!!!!!! It would really help me!