I hope things go well in your T session with her tomorrow. I'm also thinking about her circumstances. I've never been pregnant (I'm male!) so I've got no idea what it is like, but I'm guessing that her emotions are being thrown around quite a bit by her hormones for the last year, and won't stop for another few months. I don't think it was a coincidence that my wife's BPD symptoms hit their most severe as she was Peri-menopausal and going on an involuntary emotional/hormonal roller coaster ride. Perhaps this will improve considerably later.
But that doesn't help you cope with today's situation any. Let me try to offer you some help on your current issues.
The main thing I struggle with is lashing out at her when I feel attacked. It is a knee jerk reaction that is very hard to change. I want to instead tell her how I feel. Anyone have any tips for this?
When a pwBPD gets dysregulated, nothing good is going to come out of their mouth. Your best bet is to get away and not engage, until that mood passes.
You've also noticed that you tend to lash out yourself at those times. When you are calm later, you know that you were not improving things. So when you disengage, you are protecting yourself from her and her from yourself.
This workshop has some specific tips on how to get away at times like this:
How to take a time outThen the other main problem we are having right now is that when I do express my feelings she is taking it and everything I say with a very negative interpretation and twisting things around to the extent that I'm made to feel guilty for my feelings.
My suggestion is for you to accept that she doesn't have the emotional capacity to deal with your feelings. If something is bugging you and you need a sympathetic ear, don't ask her to do more than she is capable of. Do you have other friends you can talk to, or family members who support you?
I think she is going to hold off on coming back home for some time now. She wants to give me space to work through my issues. This just feels like more blame shifting to me though.
You may well be right on the blame shifting, but I recommend you let that one slide (at least for now)
First, there will be times where you DO need space, and if she respects that and gives it to you, that is very helpful.
Second, it sounds like she is needing space and projecting it onto you. The important part is that she needs space. Let her have it. If you crowd her or chase her when she needs space, it will just make things worse.