Replying to I think i'm screwed

uhhh shit. i dunno, i've been getting decent grades this year and now for some reason i dont give a shit... i'm failing subjects i had 90's or above in (except math, that always brutally rapes my GPA) ...i KNOW i need to give a shit and i WANT to give a shit, but i just dont! like i go to do somthing like i normally would then i just flake off and say fuck it and some how talk myself into saying "this shit is pointless, dont even attempt it." i'm a junior in high school. am i fucked?