Dad married another woman

I am in my 30s. We are a Christian family, living in a predominantly Muslim country. In 2010, I found out that my Dad got a second wife “the muslim way” and they had a baby boy together. and it’s been 10 years, and I haven’t really processed it. My mum, for her own reasons “you don’t get divorced in the church”, decided to stay together and forced my Dad to “divorce” the second wife and to have no contact with the woman or the child. But honestly, I don’t see their marriage as healthy.

I can intellectually see the “unconditional love” teaching would benefit me if I just unconditionally love my Dad. I want to do it. But I don’t believe the thought yet. Anyway, let’s try a model

C- Dad married another woman
T- I am unlovable
F- worthless
A- I don’t look after myself. I overeat. I don’t take responsibility for my actions. I am treating my Dad and my Mum and my husband and my kids like pieces of shit. I am already worthless anyway, it doesn’t matter what I do or don’t do or how I treat other people or other lives
R- I am treating myself as worthless