I do not understand clinical psychology like some of you do, but I don't like over use of spectrum disorders like BPD...of course, it may be completely legitimate in this case, but don't be afraid to call a selfish brat a SELFISH BRAT. Sadly, I was that selfish brat in college and was diagnosed with BPD and bi-polar disorder. I never fully embraced my diagnosis though, and that turned out to be a really good thing. In retrospect, I can't help but wonder if my doctrs were just lumping me in with all the other selfish unstable immature people(and there are alot of them)-- If I really did have these rather serious behavioral illnesses, shouldn't it have been harder to change things and get my head on straight? I didn't want to stay on the drugs the Drs gave me, and out of sheer stubbornness decided I would figure it out-- some people i trusted were honest enough with me to reveal that I was just plain selfish, and also scared, so getting healthy, getting away from bad influences, and getting counseling were my best path. I had serious growing up to do, and getting married to a very strong minded guy(senior year in college) exacerbated AND helped my issues. I probably should have waited to get married, but hindsight being 20/20... I almost hope yr wife doesn't get diagnosed as BPD, the 2 people I know who have been loud about their diagnoses just use the label as an excuse to whine about why everything should go their way and how unfair things are, and that other people need to bend bc of their illness. I suppose some Dctrs have trouble saying, "You don't have any disorder other than pride, entitlement, and old-school meanness. You are a b$#@! and unless you smarten up, nobodies going to want to be near you". Just my opinion.
My DH (we've been married 16 yrs) has serious rage issues, and his anger helped me to realize I needed him to form my own identity. Every time he had a bad day, I would whine or sulk, or give him plastic-smile-face, all the while resenting him and keeping tallies against him. Through IC (Christian counseling, Im one of those Bible-thumpers yr W doesn't prefer) I realized that alot of my demanding/ narrow-minded/ vengeful/ ungrateful/ unstable behavior was due to deep rooted insecurity from sexual abuse from my childhood that I had never dealt with. Yikes. 1st time Ive ever said that in "public". Still painful. Moving on-- Its OK to feel pain and fear, just not to take it out on everyone around you, as yr W seems to be doing. I realized I could not control everything, and that I need to be responsible for my own happiness and actions. That meant eating healthy, not staying out super late, ditching stupid unhelpful juvenile friends, and getting involved with positive people who would call me out on my crap. (For me these helpful people were church people, they hold me accountable and love the hot mess I am to this day.) Shockingly enough, doing these rather obvious things brought me to stable enough place that I could receive correction, speak kindly when frustrated, deal with lack of instant gratification, and take responsibility for my actions. It also gave me interest in doing things outside my house without my DH-- it took me a while to realize that it's GOOD to have separate interests and hobbies.
Things are still rocky in my house sometimes, changing a mindset away from self-focus is a lifelong proposition. Also, my DH is in counseling for his struggles. It is totally valid for you to go to IC to vent about yr selfish demanding hurtful W. If you don't get your frustration at her out somewhere, it'll likely end up spewing out on her. Not that she doesn't deserve it, but keeping yr own nose clean will definitely be an asset, especially if you pursue divorce and it becomes "he said-she said".
I believe your marriage can be saved, but it's gonna take HER choosing to turn around. If you are one of those Bible-thumpers, start praying-- HARD.
Also, having been on the receiving end of someone raging on you; don't take it, Pag. Tell her in a calm moment that if she drops an "F bomb" on you, you'll walk away and the conversation is over.
All the best to you, man.