I pretty much agree with the others on the letter ... shorten it, if it's been said before then don't repeat.
But - one thing I will say is don't get your expectations up. You said in the letter you weren't looking for a response. If you are deep down hoping for one then you may well be disappointed.
I had a talk to my H last night about what he was going through when he dropped the bomb on me. he said he felt utterly miserable. he had no enjoyment of anything in life, he felt lonely and really down. He doesn't want to call it a depression, he describes it as being "down". He did also say he never seriously considered getting a D. It was all about him, how he felt. OK, our M wasn't great but that wasn't the only contributing factor. There were a lot of factors (eg his job) over which I had no influence. He wanted to feel happy again but felt lost. Our M problems I managed to resolve relatively easily, but as I said there were other areas affcting him which I could not help with at all. I had to sit and wait it out.
Just a little insight into what MAY be going through your H's mind.
Bomb (ILYBINILWY, don't want to be married)Sept05 Seperated Sept/Oct 05 Oct 06 - H recomitted July 11 - I am now a WAW.