Hi room_2_live,
I'd like to welcome you to bpdfamily. It helps to talk to people that can relate with you, you may have people in real life that can, I'm just talking about myself when I say this, I found no one could relate with me. My ex wife is also not diagnosed and family members and friends don't understand BPD, BPD is an invisible disorder.
The disorder is directed to people that are closest to a pwBPD, unless your really close to that person, you shouldn't see the behaviors. Some family members said that she can't be mentally ill if she's not diagnosed, that felt incredibly invalidating because it means, to a degree that way I say is not real. Many people that are mentally ill, are not diagnosed and the people that are diagnosed don't believe that they are ill, there is a fraction of people that acknowledge that they are and do self work to get better.
It also helps to concurrently work with a T and a support group. Do you have a T? How long have you been together? Are you married? Do you have kids? Lastly, what BPD traits do you see?