I know its long but i need your help!!!!?

Im in 6th grade and well I have been doing pritty bad in social studies and math ( both tought by the same teacher)..I dint think anything of it untill i kept failing both of them on my report card agine and agine...Every report card I have gotten i have failed both subjects!..My main bad subject is math I just dont understand it at all!...every time i get it...but then i cant remember what i got the next day..I have rumitorthi arthritist caused by lime disseas witch could have something to do with it....Well now im going to fail 6th grade because of it...but i just cant and am very scared!...Is their anything i could do that would help me from failing 6th grade other then doing well in those subjects...i know its april and school ends in june but i cant fail please help!