Hi francisunderwood,
Welcome to the BPD Family
I'm so sorry your partners anxiety is at such a high level that it's causing him to act out towards you and your kids, that's definitely not a fun place to be.
I wanted to suggest a tool that might help both your partner and your kids and that's validation.
Validate your partner's feelings (not his negative actions or invalid statements) you might try using what we call SET (Support Empathy Truth)... .something like... .
I really want to help you get through this surgery, and I know its scary surgery would make anyone nervous but it's really important that you have this done for your health/blood pressure/diabetes/whatever the reason. The kids and I care about you and support you.
You can also ask questions... .what is it that you are most concerned about? How do you think we could lower your anxiety level? and validate his feelings when he answers. Imagine that you are talking to a 7 year old going in to have their tonsils out not an adult that might help too.
In terms of the kids listen to them validate what they are feeling and ask them questions... .I'm so sorry dad yelled at you why do you think he did that? Do you thinks he's worried about his surgery?
Below are some links that will take you to more information on Validation & SET. Hopefully trying some of these techniques will help lower your partners anxiety level so helping the rest of you.
ValidationIs listening with empathy to another's point of view, their feelings or their experience. It involves giving your full attention, and listening to both the feelings and the needs being expressed, and trying to understand by putting yourself in another's shoes.
https://bpdfamily.com/content/communication-skills-validationhttps://bpdfamily.com/content/communication-skills-dont-be-invalidatinghttps://bpdfamily.com/content/communication-skills-dont-be-invalidatinghttps://bpdfamily.com/content/communication-skills-dont-be-invalidatingSET https://bpdfamily.com/message_board/index.php?topic=143695.0I'm really glad you decided to jump in a post, I know other members will be along soon with more ideas.
Take Care
Panda39