How do i actually study effectively?

so i have my final exams from 8th march... and l studied literally nothing have 5 subjects and hv done nothing my focus is zero like i cant study for even 10 minutes.. i am addicted to doom scrolling i am not able to remember what i learned... i have subjects like maths, sociology, economics n politics... and i dont know how to study from zero... i am physically and mentally unfit .. keep feeling dumb.. am not consistent at all i just am not able to study anymore.. tried pomodoro doesnt work with me.. tried all possible techniques dont work if i throw my phone away i get to my laptop if i kick both away i feel anxious cant focus keep craving my phone keep either craving music blasting my ears... pls help.. ifeel like i am in a drain where i am just going deeper with no escape no growth i see all my future going down and am helpless