Hi Nat!
I'm sorry for what brings you here but I am glad you found us.
You are definitely not alone here and I hope you will settle in, read and respond to other posts, and I think you will quickly see that we understand what you are experiencing here.
As
2loyal2long mentioned, there is a tools section at the top of this board. We have many resources here to help you communicate with your ubpd (undiagnosed bpd) spouse.
As for your own support, have you considered seeing a counselor for yourself? It can really help to have someone face-to-face that can provide support for you because these relationships can be mentally and emotionally taxing. Marriage groups and friends are great, but it's hard to find people who understand the depth of the issues that bpd relationships can present.
I hope you will share more when you are ready. Again, welcome to the family!