Is there a private room you can excuse yourself and go into to be by yourself?
If not, is stepping out, maybe just onto the porch, maybe for a short walk around the block something that can help?
Just knowing that you have an “escape” available can be a huge help in calming your anxiety and reducing your stress.
Panic attacks are very unpleasant – way beyond normal anxiety and apprehension, which may be what you’re experiencing.
If you actually experience full-blown panic attacks due to relatives’ Yom Tov proximity, and simply removing yourself from the premises isn’t an option or doesn’t work, you may want to speak to a professional for other ideas.
Obvious disclaimer:
I’m no pro, nor do I know you or your situation.
I’m just a poster trying to give some helpful advice based on conversations with a pro about panic disorders and their triggers.