Impact of Porn Addiction and Daily Masturbation

Hi All,
I have been masturbating every day for a long time now and I dont feel good about it. I feel sad and like a loser
But I am unable to go sleep without masturbating to porn or now even looking at girls pictures on instagram. I feel I am becoming more and more sad in my life. I am married and have a 4 year old. I have a sexless marriage so thats to my frustration and my masturbation habit.
Somebody please help me and tell me how do i cope up with all this. When its night and I am alone in my room, nothing can put me to sleep except masturbation