Realized I was the angry dad and changed it
Short version: I was irritable, yelled at the kids over stupid stuff, took my work stress out on everyone. My daughter told my wife she was scared of me and that hit different. Started therapy, learned some stuff about my own childhood, started meditating and actually dealing with my anger instead of just exploding. It took months but my kids are more relaxed around me. I'm more relaxed around them. I actually enjoy being dad now instead of just being the guy who pays for things and says no to everything.
Man, that's real growth. Work stress leaking onto the kids is something a lot of us struggle with but don't talk about. Sounds like you're creating a totally different environment for them now.