So I have this really close guy friend and we were talking about our deepest secrets, I told him how I used to cut and he told me his thing is worse. But he wouldn't telll me what. He aid its not on the guidelines of cutting, and he said its not something he did or something someone did to him. Not drugs, not sexuality, not abuse. He said its something he hides well and hasn't told anyone and that its something he could get counseling for. Im very worried about him and not sure what to do. Any ideas?

Something he did ? Or is doing?

Also perhaps they did not want you to feel so bad and wanted to sound "worst" Since they did not say what it was, and you have no idea. Saying it was not any of the worst?? There is really no advice except just be friends

If you have a really close friend, then you don't need to ask total strangers about what he might be hiding.
It is your 'job' as a friend to be there for him, not speculate about him, nor know, nor fix him.
Keep telling him gently that you are there, you are his friend, you will not judge, you will not pry either.