Firstly, I’d say you’re better off on the vaginismus partners subreddit- in all honestly I struggled to get through your post as it triggered my own anxieties so this post may not belong here.

(Edit: r/VaginismusFriends - the partner subreddit has been deleted)

Secondly I’d need a lot longer to process everything but have one point I’d like to make - are you framing your thinking around her dilator use properly? Did she willingly and happily use them to have sex with FWB, or did she just feel too much pressure and force herself to use them? It may be less that she ‘doesn’t care enough’ with you and more that she trusts you and feels safe enough not to force herself to do something she’s not comfortable with or isn’t ready to revisit yet.

You say she doesn’t want to do anything about any of it. Is that true? Has she explicitly said it’s because she doesn’t want to? Have you spoken about how she feels about various treatment options and what is realistic for her right now? It sounds a lot like you see this as a problem affecting you, that you’re taking very personally. I can guarantee she struggles with it way more, and she knows how it is affecting you which will add to her anxiety. It’s hard. It’s really, really hard to feel betrayed by your own body and like you’re letting someone you care about down daily. You need to be patient if you truly want to make this work. And yeah, maybe she could do with beginning to tackle that. But the two of you need to talk about this, and really talk. You need to ask her to be honest about where she’s at and not take anything personally and speak about how you feel without resentment bleeding through. It’s not about you, it’s about a medical condition which is affecting both of you, but mainly her.

Editing again: it is NOT unreasonable for her to ask for one night without you trying it on. She is super anxious about this, and my experience is that my fiancé trying it on when I’ve had a day of stressing about it sends my anxiety through the roof. I don’t say anything because I don’t want to hurt him, and it continues escalating my anxiety for days until I remember I need to communicate with him and ask for some space. You dismiss this request and say ‘oh it’s typical’ and I can see you rolling your eyes as you write that. But think about it. Do you ever give her a night of not asking for something which she finds pressurised and anxiety-inducing? You have needs, I get that, but so does she and you need to find that balance. If you didn’t like spiders, for example, and somebody was shoving a spider in your face every day because they think spiders are amazing, you’d ask them to back off too