Can you help me write an apology letter?

This guy told me he thought he wanted to date. But then realized that he didn't want to. He apologized to me saying that he know it wasn't fair to me. I got so upset and lost it I went off on him completely. Because I was really hurt and I said a lot of things to him via text. I called him a liar and said a lot of things that I shouldn't have. I called him on Thursday to talk to him and apologize. But he didn't answer (I'm actually surprised he hasn't blocked me). So I want to write a letter and leave it in his mailbox.

So far I have...

I regret my obnoxious behavior. Words cannot express the sadness that I have been feeling. Since I lashed out at you. I let my emotions get the best of me.

Can you help me write an apology letter?
Post Opinion