Suggest Remedy Pain In Lower Left Brain And Memory Loss

Why i have pain in lower left brain like headache and i am struggling to remember what i studied? am struggling to remember what i learned in school as now i graduated this year on may finshed high school..but i forget what i studied even i can't explain to my brother for his maths grade 11and even simple questions i can't answer though i was veery very good in school.why is this happening to me .even if i ask myself what i learned hard for me to remember .i say to myself to revise all books but that is impossible.why?.why is this happening to me.?.and i feel hard to return into the person i was before .this is hurting me .and wonder who am....and how i was before i .afraid to forget my ,name..thought of suicide else runaway