It must be really hard on you to have not slept for 4 straight nights. I am sure it's not just your head and eyes paining due to sleeplessness but also the exhaustion of whole body and mind. You are quite strong if you are holding on so far. As it's only since 4 days, sleeplessness clearly has an immediate reason behind it. It might be anything ranging from physical ailment to emotional states like anxiousness, excitement, confusion or even the overflow of thoughts. Either you know the reason for this sleeplessness or yet to find out. In either case you would need to consult a professional immediately so that they can help you handle the situation and get back to normalcy. Please consult a psychologist or psychiatrist so that they help you further.
As for today, please try to relax and calm yourself down, every problem how much ever serious it might seem comes with a solution.
Take Care & try getting some sleep.