I don't know if this will help, but when I left as an adult child, I finally had to tell my parents that I loved them no matter what. and i wanted them in my life, but they had to respect my choices as an adult. I assured them I would not attack their beliefs if they would respect mine. Then I left it alone until they were ready to have a relationship. It took some time for them to make peace with it, now we have a good relationship, but religion is never discussed.
i have a better relationship with my parents than my siblings that are jw's, but it's because we have boundaries.
Good luck. I hope you can find peace.