Tilbury told investigators he and some friends ate mushrooms and drank a tea made from the substance Tuesday afternoon. His friends left his house shortly after and he fell asleep.
"Tilbury said he woke up and it felt like it wasn't real," deputies wrote in the report.
Tilbury told investigators he felt like he was awake in a bad nightmare and could not escape from his house.
"Tilbury said he thought if he shot himself he would wake up from the bad dream," investigators said.
The teen told deputies he walked into his parents' bedroom and got a .22-caliber rifle. He then went back to his own bedroom, sat down on his bed, put the butt of the gun on the floor, removed the safety and fired once into his own forehead.
"He said after he shot himself he didn't wake up from the bad dream," the report states.
Tilbury tried to clean the blood that got on the carpet, wrapped a bandage around his head and walked outside. He saw a man who he asked to take him to the hospital.
A deputy asked Tilbury if he wanted to kill himself and he said, "No, I just wanted to wake up from the bad nightmare. I am happy and I love my life."
A deputy collected the bullet a doctor removed from Tilbury's forehead.
Tilbury's mother, Mary Wilson, was reached today but declined comment