Nobody likes to be yelled at, but your situation seems especially complicated. From what you're saying, it sounds like you're getting the brunt of your father's frustrations with something that has nothing at all to do with you. And that it's become sort of a pattern.

The first thing I would suggest is that you keep in mind that patterns can be hard to break because people so often don't recognize them; your dad may really not have any idea that he is yelling at you in such a repetitive and upsetting way.

I would also suggest that if you decide to try and speak to him about this again, make sure you pick the right time and place. Your dad will probably be much easier to speak to when he's not stressed out; the heat of the moment is not a good time for discussions. (Some people like cars for conversations like this because with a "captive audience" it can sometimes be easier to get things resolved.)

As for your father's relationship with his fiance, it sounds like they might benefit from some counseling from an objective outsider. It's not your job to suggest it, of course, but what you can do is acknowledge his stress about that, if it feels comfortable. Your point being that, whatever the cause, his yelling bothers you and you want it to stop.

However you decide to handle it, you might want to visit our family shoutout to see how other girls deal with resolving similar conflicts.