Propagandizing myself?

So I completely philosophically understand that my thoughts about my dad are causing my feelings. But the thoughts are deeply entrenched, so making the new thoughts BELIEVABLE and not feeling like I’m feeding myself propaganda is what I am struggling with. So is this just a time thing? Work on ladder thoughts everyday until I believe them, and then move to the next rung? It’s okay that it’s not an instant jump? Clearly I was hoping for a quick-fix to this LOL!