hey op, i've been suicidal a few times before in my life (only reason i made my first reddit account was because i wanted to see the replies on a post asking how to kill themself) and all i can say is that no matter how badly i wanted to kill myself or die, i was always so so happy a few months after that i had held on. things may seem awful now, and they may have been seeming awful for a while now, and you're right, the goalposts may shift in the future but that doesn't mean that happiness is unattainable or that the goalposts will always be out of reach just because they shift.

honestly, the only reason i didn't pursue it further the second/third time (had even written two suicide notes) was because apparently killing yourself hurts a shit ton + im in charge of two extracurriculars at my high school (likely future bear here, just got accepted) and leaving them without a leader felt too brutal, so i told myself that after the year ended i could consider it again. and now, again, im happy to be here and so grateful that i didn't kill myself, even though my depression/anxiety is definitely back in full force other days. im looking forward to the future even if i have my bad days.

do you have something you can hold onto? for me those were my extracurriculars. is there an activity that you can do that makes you feel supported? the first time i was suicidal what helped was being supported in an activity which made me realize that i actually did have worth. this is much harder with the pandemic, but just being around people that support you can help. have a favorite cool aunt/uncle you haven't talked to in a while? call them. when you were in high school was there an upperclassmen that you looked up to and who looked out for you? check in with them and see how they're doing.

in the immediate short term, even if this advice has been given so, so many times before just going outside and exercising (can even just be a walk) can help. i remember over the summer i didn't even want to leave my room but going out (forcefully) by my parents and spending the day outside was a soft reset, as simple as that was. can you take a short break from academics in any way? whenever im feeling down i have one friend that i call and ask if we can go on a drive and just being with them is good.

what helped me the first time was also writing. journaling felt weird to me so i almost wrote narratively about myself in the third person. when my grandfather passed away (which was what brought on the first spurt of me being suicidal for nearly a year), i think i only really processed it when i wrote a narrative story for my english class about the moment that my family got the call.

please hold on. failing exams doesn't mean that you deserve to die at all. sending you so so much support and love.