I read your post,

To be honest I think he will just turn things onto you like he has already shown his ways.

Will this help your relationship? I doubt it , I think he will just not understand what your saying and blame you all for it, even the undeniable truth of your parents fighting all the time.

But .... will you feel better to send this? I think that's the biggest part.

Through my own Therapy I came to realize that my Mom was very emotionally abusive and why I have a particular nightmare happen all the time.

She passes away in 2003 so I had no way to send a letter or try to talk it through so my opinion might be skewed by my lack of ability to giving her a letter....

so I would say yes send it .

Just be prepared that he won't like it at all and possibly make him angry, truth often makes people angry.

Either way you decide make sure your support is in place so regardless of the reaction you will have help to manage through it all.

Send not on Father's Day , any other day would be good

(((((( hugs))))))