What Does The Bible Say About Masturbation?

Good Evening Nairalanders

I have a young friend of mine who has been masturbating since he was eleven years old and he is going to be twenty this year. His parents are divorced and he does not live with any of them.

We where talking today and he confided in me that he's been masturbating since he was eleven and that he has been struggling to stop out of guilt but he eventually stopped trying ever since he saw that it was almost impossible so he continued.

But I tried to encourage him to stop because I have been there. I started when I was in the university and struggled till 2018 when I eventually got more control. I realized that while I was still a chronic masturbator that I had almost no drive to succeed in anything which affected me a lot because I kept to my self, had no friends, felt guilty, weak and empty but my friend argued that he won't even bother trying because it was just impossible and doctors say it's healthy to masturbate, I argued that those doctors were lying and that it is not Scripturally okay but he also argued that were in the bible is it written? and I couldn't argue more cause I also relapse at times.

So please, that is why I have come here to ask for the advice on how to encourage him to keep on fighting against addiction and what bible verses can I quote for him?