Melatonin

Does taking melatonin actually help with sleeping..? Please i need help 😬😭 literally I only drank a little bit of black tea and I can't sleep ... any little bit of caffeine will trigger me. I know this is gonna ruin my sleeping schedule that I've worked so hard to fix 😭😭😭😭😭😭 I need to buy something tmrw that will help me pls !! Someone halppajjjhh!!