I was trying to say that you are the one he wants to share with, and he doesn't want anyone else to know that he has these problems. You are the special one that he wants to talk to, and he wants to keep his feelings secret from your mutual friends.

And the other thing I mentioned about jealousy, I meant maybe he wanted you to tell him when you were feeling upset. Let him know that you want to help him but that you don't know how. Confide your feelings in him the same way he confides in you, instead of talking to a mutual friend about them.