Ladybird I am sending love, support and truth your way. I too found out after 26 years of marriage my AXH had been lying to me about everything. In fact, after he came clean he said to me that he lied to me just to lie, he said he lied about things he didn't even need to lie about. Thats when I truly saw how sick he was. We owned a business together and contractors and employees would call me (well after he was sober) saying they're finding that he lies to them alot. I talked to him about it very recently and how it's hurting his business and he said he knows and doesn't know how to stop lying.
A sane mind thinks "hey i know, just don't lie", but that's not how their mind works. I don't get it, I don't care to figure it out. It's just a part of who he is and I'm grateful he's my X.
I work on trusting people constantly, but if you lie to me once... you're done. I will never accept anything but the complete truth, even when it hurts, ever again. I'd rather deal with the pain of the truth and navigate that any day, over being lied to. And as someone said, if someone can lie to you once and about something little, they can lie about anything. That's at least what I believe as well. This is a boundary I put in place for me. Integrity.