I don't really have any good tips, but I sure know where you're coming from

Actually maybe I have one tip. In addition to spending time with dad alone if possible, try to spend some time with them with someone who knows them but who sympathizes with you. Maybe you have a friend who could step in, maybe a hubby. Having someone around to grin and roll eyes with behind their backs can defuse a situation enough for you not to find it so stressful. It makes it a lot easier to rise above things.