Hi
I understand your concern.
If you have sleep around 4 am and you are not able to sleep before it then it is sleep onset
insomnia.
For which medicines like
lorazepam and zolpidam is useful because it has short latency time and they are useful in sleep initiation.
Regular
sleep hygiene is must.
Fix sleep schedule and stick on it
No day time sleep
exercise that makes you fatigue
stress free activities and meditations
Avoid alcohol and smoking
avoid heavy meal in dinner
avoid tea cofffee soft drink at night
use bed when you feel sleepy
read up to when you will sleepy
No day time sleep
no talking or use mobile in bed
calm and cool bed room
all of this will help you to restore good sleep.
If still you have sleep problem then need to asses your
depression and antidepressant medicines.
Thank you,