How can we better communication and reassurance with bpd?

So me and my girlfriend have had troubles with communication. I have BPD and she doesn’t. She is very closed off emotionally and says things that accidentally trigger a split which results in hours of fighting and both of us not feeling heard because I’m seeking reassurance and she thinks I’m just not giving it up (whatever the subject is). She gets frustrated with me for repeating things in order to get her to respond and a reassuring way and I get frustrated because she gets annoyed by me “not letting it go” and I feel rejected. This results in me having severe relationship anxiety and seeking even more reassurance because I’m afraid she doesn’t love me or is cheating etc. (I realistically know she is not but my anxiety tells me other wise) we love each other very much and would love advice on how she can show up better and ease my mind but also what I can do during a split to keep myself from jumping to extremes in my mind.