She said in the letter she loved Ryan and it was always Ryan for her. And they had no future and that she didn't love him and never would. That made him go nuts and start drinking and climb up a cliff i think he wanted to die when he read that.
I think she said that she loves him in a way but dosen't want to and really can't go any farther with him... she loves ryan and that she can't handle it... and i think he was soo angry that she pretty much said she won't be with him that he jumped off that cliff..... and even though ryan tried to save him..... but he also was drinking... But yea i think it was something along the lines of that