Fortunately it wasn't to the end of his days. Suffered for 50 yrs tho, undiganosed PTSD, drank too much, got divorced, said he actually walked into the ocean at one point. Never got help or told his story at all until he met an author who wanted to write a book and turned his life around. They married, wrote several books together and lived happily ever after.
Once he started talking he practically never stopped lol. There are hundreds of intervirws and oral histories on you tube. Hill said he only got over the guilt when he finally visited Dallas again, went to the Sixth Floor Museum and looked out that window. Said he realized neither he nor anyone else could have saved Kennedy. Without the bubble top, he was a sitting duck. The Clint Eastwood movie, In the Line of Fire is based on his story.