LTD, I had thought when I read the first quote. (I have some difficulty with the last part of the second one, mind.)
It does take two to make (or break) a relationship and there isn't much peace to be had without forgiveness. You didn't have to take him back 8 times - that was your decision. I've realised that the more I look at situations and own my part in them, the less forgiveness of other people I have to achieve. At one time, I blamed everything on my ex. Now I see that I contributed to my own unhappiness in (at least) equal measure.
That said, the standard business response of "I thank you for your letter dated xxxx, the contents of which have been noted" might be well borne in mind in this case. (not to write exactly, of course!) Anything else could be used against you (as already mentioned) and/or create unnecessary drama.
What support have you got for yourself through this difficult time?