I hear you on feeling overwhelmed, I watched my partner go through the same thing with his uBPDex. It is a constant bombardment of all kinds of stuff/drama that just becomes too much, wears you down and you give up on your position or what you want/need just to make it stop.

One of the biggest lessons I've learned here is the only people we can truly control/change is ourselves. You can't make your wife or anyone else do, think, believe something they don't.
In making changes in how
we respond or don't respond to the pwBPD (person with BPD) in our lives we create ripple effects that change the relationship dynamic. We often go round and round, over and over again doing the same dysfunctional things...wash, rinse, repeat. It's about changing the dysfunctional dance to something else, to something better, and since your wife isn't changing anything, that's where making your own changes comes in.
What would happen if when the yelling started you told your wife that you want to have a conversation but maybe it would be good for you both to take a break so everyone could cool down and you went for a short walk? One small change on your part, that could change the entire interaction.
Boundaries to me is one of the biggest tools we have...a boundary could be that you will take a break/walk if she starts yelling. This is about protecting you (you do not have to stand there and take verbal abuse) it is not about punishing her it's about cooling down so you can have a conversation instead of a screaming match.
Below is a link to Do's & Dont's in a BPD Relationship that you might find helpful...
https://bpdfamily.com/message_board/index.php?topic=62266.msg591101#msg591101I'm glad you decided to jump in and post, there is a lot of support, tools, ideas, and members that have been there here on this site that can help.
Hang in there,
Panda39