Pete wrote, "When I was younger and several times throughout our friendship he helped me get through some rough mental health stuff."
But, it wasn't just a "Hey, how ya doin'" call. Pete says Bob was genuinely concerned and wanted to help ... "He stayed on the phone with my mom for hours trying to help in anyway he can -- connecting us with doctors and new things we can try. He would check in on me and make sure I was okay."
It's one of a slew of tributes to Bob. TMZ broke the story, he died Sunday in an Orlando hotel room at age 65.
Pete ended this way ... "I love you Bob. It was an honor to know you. Thank you for your kindness and friendship. My condolences to the family."