I feel like my husband is emotionally abusive to our children

I love my husband. We've been together 24 years. Together since high school. He's a great husband and was a great father until our kids started going through puberty. He started seeing my 18 year old son more as competition it feels like. He got very verbally abusive towards him and didn't like me giving love to my son. My dad told me it's normal and that no man wants to share his woman with another man. Which is weird because that's my son. It changed AFTER my son came out as gay. After that my husband stopped being so possessive of me towards him.

I find it funny how he used to get angry when me and my son were close but he gets angry over our daughter dating and that's what this is really about. My daughter is 16. My husband didn't really like her dating. Accused her of having sex. She has had two boyfriends who's parents made them break up with her because my husband threatened them with a gun. I don't think that's okay but I did think that that's something dad's just do. I'm not saying it's right. But my daughter sent me a screenshot of messages between her and my husband and if this is how hes acting towards them I understand why the parents made them break up with her. This seems so abusive towards her and he won't get help. When I confronted him he stood by everything he said to her. What else can I do? Please don't comment leave.. I know most people don't take marriage seriously anymore and think they can just leave whenever but I do take it seriously. Marriage is forever. I'm not just gonna leave my husband. But I do need to know how to go about this because this isn't okay

Edit: He never wanted our daughter to date but was fine with our son dating which I don't think is fair. This issues with our son was he would get jealous of our close relationship up until our son came out as gay. He also will not go to therapy. This change started happening when they started going through puberty. I believe if we don't allow our kids to date they'll just do it behind our back anyway. I'm also not going to tell one kid they can date but tell the other one they can't. I also think it's weird to assume I pick favorites. I'm close with both my kids in different ways. I find it very typical "blame the woman" to try to find a way to pin my husband's behavior on me.