There is a story behind the name! I'm not that vain! I didn't give it to myself! But, thank you! (((((Dangny)))))
I have a feeling that he already knows that the affair isn't ok, that you are willing to reconcile, and the conditions. Am I right?
If you are going to say it in a letter, it needs to be WAY stronger than that letter. I think there need to be a lot fewer words, more facts, less feelings. I think the first couple sentences would be taken as an effort to send him on a guilt trip. Of course, after that, the rest won't even matter.