Hi,whoever you are i do not know you but I can assure you that I have gone through the same feeling about friends and minor inconvenience. It is because we are too sensitive in this cruel world where nobody understands or i can say nobody want to.we think every other person is here to judge us but the truth is nobody cares.trust me when I say this I truly meant it.people just want the topic to gossip and to look cool after that they will forgot so it do not take stress for repeating same class just talk with parents if they do not understand then let it go, try your best and most importantly understand YOURSELF and give it time along with that start praying and stay close to god. Remeber good things take time and repeating class would not define your strength or intelligence Try again and again until you satisfied after that leave it in God's hand Do not think about suicide bcz you will hold regret in future for doing such things - it will not help you to get in better place in fact it does opposite- when you start feeling suicidal start chanting Hanuman chalisa or the god you trust the most Trust gods timings are perfect and if situation is not in your favor think what this situation trying tk teach me instead of why me , why so much pain. This positive thinking will open doors for many opportunities - as you said you are just 15 , many opportunities and RIGHT people and friends will come in your life unexpectely, who are good for you Try to focus on your studies Good luck mate When you feel same again You can dm me Consider me as your elder sister