His distraught sister Chanie has told Cornwall Live of her heartbreak.
She said John, who had struggled with depression and anxiety, posted a photo of himself and a “goodbye” message to Facebook shortly before he died.
“The outpouring of grief since his death has been overwhelming. So many people adored John and it’s been incredible seeing how many lives he’s touched. I want people to know more about who he was as a person,” Chanie said.
“I don’t want him to be a nameless guy who jumped off a bridge. We have always been a tight-knit family, John and I were like twins growing up. We were only 13 months apart.
“He was always there for me, for everyone. He was so generous, kind, and funny.
“If ever you needed him he was immediately there offering everything he had.”
Chanie had spent Tuesday night with John enjoying a takeaway at home in Illogan. She said he seemed happy and, in recent months, had shown signs he was overcoming his mental health challenges.
But now Chanie says she is devastated and her life will never be the same again.
She added: “He bought me takeout, told a few jokes and that was it, my darling brother is now gone.
“He touched the lives of so many people, and those who truly knew him adored him. He suffered with depression and anxiety for most of his life. He seemed to be getting better in recent months and he seemed happy the night before he died.
“Please hold those you love close to you, please tell them how much you love them. I am fortunate that I told him I loved him before I went to bed that night. I am devastated, and feel utterly lost. My brother, my best friend is gone and my life will never be the same again.”
Chanie said that John loved music, science and reading books about everything from world history to science fiction epics.
She added: “He had a thirst for knowledge and was constantly educating himself about everything that caught his interest. He loved to make people laugh, if you were upset he’d have you laughing within minutes, because it hurt him to see others in pain.
“He loved bees, the beauty of nature and he adored cats. He was a son, a brother, a nephew, a best friend and the type of person the world is now poorer for losing.”