My mom cheated on my dad and got pregnant with another guy's kid. It caused a really messy divorce including all the components of nasty divorces. I'm okay with it now. It was hard having my life so drastically and suddenly changed. OP just accept that your parents are complex people who are not even close to perfect. But they are still the people who did all the good things for you that they did and made sacrifices for you. Try not to be too harsh with your judgment.