Hi Jeep. Write the letter then burn it. You not giving yourself time to let your feelings settle Firstly you do not want this version of your W back. , you deserve much better.
You both made mistakes but only one of you acted in a horrible manner and disrespected the other.
Only you know if you can truly get past what W has done but you are not in a place to decide that yet.
Give yourself time to accept what's happenedc and let your feelings settle
Please do not send the letter , it will achieve nothing but show W you will accept anything she does