How Do I Improve in Math?

i suck at math. and im going into the 8th grade. how can i improve in math? i mostly get D's or C's but i at least want a B. please be thorough and honest. i know i should review the stuff and i do but sometimes i just don't understand it at all. a lot of ppl in my class say,"Oh its so easy.." and it just bugs me that im practically the ONLY one who has low grades in math. the more and more ppl in my class tell me its so easy the more i want to STRANGLE that person because he or she does NOT know how stressed i am... =.=