My JW mother was all about the end of the world in 1975 and my non-JW dad made sure we didn't miss out on a fairly normal upbringing with birthdays and Christmas and the like. I went to many meetings, was told to fear the end of the world. I don't know that Jehovah's Armageddon was all that real to me, but JW's was the only religion I really learned. I saw a fellow student, Natalie, raised more hardcore JW and she had to leave the classroom for holiday stuff and she didn't say the pledge.
My parents divorced, Mom was DF'ed sometime shortly after 1976 started and went back a few years later. As a young teenager, I wasn't interested in going back with her, so I did not.
I feel for others. It seems I managed to escape many of the "growing up JW problems." I get it, because I have heard it and saw it happening to others. Certainly, I was changed by my JW childhood experiences, but not in such terrible ways as others.
Your letter should be very therapeutic for you. I hope it helps. Writing about things helps me immensely. I wrote a letter to my mother long ago and destroyed it so it couldn't accidentally wind up in her hands.