How do I overcoming insomnia? 21st day

Ive been struggling with masturbation addiction for about 6 years. Unfortuately, I've came across porn since I was 13 years old and have been jerking off for the past 6 years of my life. I knew it wasn't good for me, but I failed Everytime I tried to abstain from the addiction.
Here are some of the health problems I'm running into:
I'm experiencing
bad memory,
brain fog,
Oil secertions
and the feeling lethargic during the day. Due to excessive masturbation and poor health habits(staying up late+long sitting in front of computer)
I slowly turned uglier for the past 6 years. My eyes look dull and sluggish, with eyebags popping up, the skin looks darkish yellow with swollen/saggy cheeks.
I was shocked when I compared myself with a picture taken from years ago. In that picture, I see a handsome, bright looking young man with eyes full of energy. Now looking at myself, my demanor has turned wretched, my complexion dull, and eyes that look dead and inferoir. Although the features are somewhat similar, the difference in spirit and energy is night and day.
I used masturbation as a form of pressure release every night, sometimes several times a night, then my health took a turn for the worse. Other problems such as scrotum damp ess, kidney pains, shortness of breath and eczema has arised due to excessive masturbation+long sitting+staying up late.
I vow to reboot to recover my mental and physical health.
Its been three weeks. And despite going to bed early, I still have trouble sleeping. I go to bed at 10:30 and still awake at 12:30 sometimes even later.
Anyone have any tips?

 

The tips are certainly helpful. I am now able to fall asleep in less than half an hour on most nights.

Stay strong brothers!