Sleep insomnia is affecting me

Does anybody know anything that may help with sleep insomnia? I want to try as many things as possible to get through this very stressful week. I haven’t slept in 2 days because i havent been able to physically fall asleep, even though I’m really tired and sleepy. I will just be in bed for 8 or more still wide awake and just “resting”, but I still feel terrible in the morning. I took my OB exam today and failed it because I wasn’t able concentrate and look at the screen too long, so I just started guessing on every single question even though I been studying for this exam for five days now.