how can I validate how they are feeling but also stand up for myself at the same time?
this is not what validation is for.
if i punched you in the face, you wouldnt stand there and show me sympathy, or try to validate my feelings, right?
validation is something to be used constructively, in times of calm (or before things get out of hand). people with bpd traits thrive in a validating environment.
when things have broken down past the point of no return, there arent magic words to use to get your partner to chill. and in a lot of cases, that wouldnt be a good approach for a multitude of reasons.
the simplest thing in those moments, is to focus on
not being invalidating, and in general, not making things worse/escalating.
I usually say I'm not going to stand there and listen to negative things being said about me
this is JADEy, and your partner is guaranteed to say "oh yes you are".
a time out can be good, healthy, necessary, but how we use it can be tricky. you know your partner best, but you want to finesse it in a way that it doesnt come off as punishment or "getting away from them", because thats often when our partners will ramp things up.
so what happened? what led up to the argument? what was said? lets walk it through.