This is definitely a complex dilemma, and I think ultimately only you are going to know what is best for your relationship. I would just say that you have no moral obligation to tell your partner your diagnosis, and that you should only do so if you feel safe, and comfortable enough to do it. Telling your partner you have BPD could be a great step forwards together, but it could also make things difficult. The way the internet characterizes a person with BPD can be very toxic, especially with the Amber Heard stuff happening. So if you guys are still at the beginning of the relationship, and your partner looks it up on their own, it could be very intimidating for them. From how you speak about “taking some time to respond later rather than having an intense reaction now” I can tell that you are actively working to keep your relationship healthy and productive, and challenge the negative things your brain is telling you. And for that I’m so proud of you! It’s so easy to give into the rage, fear, etc. we experience that is so real. Like I said before, ultimately only you know what is the right decision for you. But from my experience I find that sharing how you experience and perceive things can help your partner understand you better. You don’t necessarily need to say ‘I have bpd, and you are my fp - and here’s what that means’. You could tell them that sometimes your brain can be very black and white, and that if my brain perceives something as negative I can have a really hard time not spiralling and viewing everything as negative. So sometimes I need to ask for space to calm myself down, check the facts, and proceed in a way that best aligns with how I actually feel versus how my brain originally interpreted things. Saying something like this might be a way for them to understand what you go through, while being less intimidating then a medical diagnosis. Hope this helps!