Trying to finish a letter...have any Ideas???

I am writing to someone who is depressed...angry...jealous...etc. I'm not really sure what to write, I need ideas. Uplifting, cheerful sentences that might go along with the one sentence I have written (*sigh) ...he says he hates me and wants me to go away. I know that that is not quite true. He is angry because I broke up with him. I assured him that I still like him, but he does not believe me. He made me promise a while ago that I would never leave, not even when he was angry or sad, and that someday I would be his hero.
Here is what I have...I need to build off of it....

Things happen and everyone feels angry, sad, or alone sometimes. We, as humans, were given the ability to take care of each other....

Tell me what you think, it may end up changing a bit...and if you have any ideas...poems, sentences, words, anything...will you let me know? I need to give this to him before it's too late....Thanks

just tell him even though your not together nothing changes...you made a promise and your gonna stick to it. youll never leave him and hell never be alone and if he ever needs strength you have the ability to give it to him.....something like that...? xx