My (31GF) girlfriend (26F) and I have been dating for almost a year. We live in different countries and typically will see one another for a week every month/month and a half. I've been living non-monogamously for about a decade, for her I'm the first non-monogamous relationship. We both have quite a bit of trauma and anxiety, hers manifests more outwardly where I have trouble sharing mine.

About a month ago I had top surgery, which is a pretty intense surgery that leaves you needing help and needing to wear a binder that restricts breathing to avoid water build-up, both for 6 weeks. Safe to say it's not the easiest thing for me, not only is asking for help hard but restricted breathing basically makes everything worse when I feel anxious. So my capacity to handle emotions has drastically gone down for a bit. My girlfriend offered to come help for a few weeks, which I gladly accepted. I was happy to get her help when I need it, especially because she's been having a lot of issues in the past half year and I've been helping her with them to the point I got drained. (The fact I got drained is my own responsibility of course and it's something I'm working on)

The trouble basically started around the time I had my surgery, when she started being interested in her good friend H's ex- partner, R. This is the first time she's developed a crush since we started dating. There was a lot of back and forth between the three of them, H being very obviously uncomfortable with two people they are so close with wanting to date one another. Things kept going between a "go-ahead with caution" and a "if you do this I don't know if we can still be close friends", which was confusing for everyone involved. At one of the go-ahead times, and before she came to visit me to help, GF texted me stuff about maybe having a date with R on our videogame date day, knowing I was hanging out with someone I've been dating for a while. We had a call about this, because this was brought up at a bad time, without checking in, and on the assumption that bc I just had surgery I'd only do half our video game date. She said she was sorry, that she'd keep the day free, and that was that.

Over the weeks after, things kept happening. She'd do something I didn't expect, I'd react badly and explain why my feelings got hurt, she'd say she hadn't thought of that or something and apologize, she'd put in more effort, but then something would happen again. (This is obviously a gross simplification of a very complicated situation). Our communication is starting to get more hostile, though we're both really trying. We just both feel misunderstood, I guess.

I feel like I'm not getting the type of compassion/empathy I need, esp because I'm at my weakest, this pushes directly on some of my biggest trauma and though she didn't mean to, she hurt me over and over for weeks. I'm scared she'll leave me for R. I feel it's reasonable for me to be scared and sensitive, and to ask for a slow pace (which is basically what I've been asking since this started).
She feels that she's already slowing down a lot and this new relationship brings her so much joy. She's scared that if she slows down the connection will somehow die, she feels I'm not valuing the efforts she's putting in. She says she doesn't want to start doing things in a way that she might resent me for later. She's hurt that I can't be happy for her right now. She feels that going fast and intense is just how she does things, it's part of the package.
We've had a conversation where we nearly broke up, but she promised to keep trying.

I think the biggest issue for me, is that I feel like I can't trust her to be there for me when I need her most. It feels like I'm being pushed into a supportive role when I feel I clearly need support more. It feels like she'd rather choose her own joy than my well-being, which is kind of a deal breaker I guess.
To be clear: I've never asked her to stop seeing R or to break things off. I've been asking for them to see one another once a week or so.

I've been developing more panicky reactions over time with this situation, so where it started with just panicking about things in the moment, I'm now on day 6 of feeling super anxious and not getting decent amounts of sleep. When asked how I feel, I respond honestly and she says things like "oh I'm sorry you're feeling that way, good thing these and these things happened to cheer you up."
I'm at a loss, and I think we might need to break up, but I could definitely use some advice.