I CANT SLEEP. Please help

I am 19, Female, 102 lbs 63 inches, no medications/drugs being taken and i do not drink or smoke.

I am having a lot of trouble falling asleep. Everytime i am about to drift off to sleep, my heart starts pounding hard and beats super fast, i feel like i am going to die if i fall asleep even though logically i know i will be fine. It feels like butterflies as if you are on a rollercoaster except deeply uncomfortable. I get a massive wave of anxiety and feelings of impending doom everytime i am about to fall asleep. I struggle because i anticipate it coming and when i finally am about to drift off it hits me again.

I have been sleeping at 4am everyday and i am miserable. I feel so nervous and anxious i cannot breath and my throat feels tight