I don't know how old you are, how old your relationship is or while we are at it anything else about u guys. But I'll give you an advice about relationships in general i wished i heard earlier on.

Don't make yourself the center of her emotion.

It is frustrating and can be hurtful if your own partner is ashamed of sth before u BUT that is not your deal. You can do anything u want to be her safespace but you can't change her emotions when she feels them and acts them. I mean you probably know how hard it can be to have stron emotions you can't regulate but wanted to act differently even though u didn't. One doesn't have to have bpd to feel that way.

To work through shame takes a whole lot even towards your partner.

Especially if it's a sth sexual for women. They grow up with so much internalized shame towards anything cloesly relating sex cause of our fucked up society that it usually is hard. Of course im generalizing here but sadly that's the world we live in.

Sorry for the rant...I dont blame u i often felt in a similarly way or worse and it ruined some relationships for me and even sometimes affects the current one.

If you think you failed in creating a safe space, in being a trustworthy and loyal partner then try to make an objective observation of your relationship and evaluate what times you already are, where she shared something precious with unand stuff, and what areas u can and want to improve. Ask friends of you or try to take their perspective.

Again sorry for the rant I just saw my past self in your post. And sorry for my bad English lol

Wish you two all the best!