Welcome to the board! 23 years is quite a long time to have to deal with BPD behavior. I'm sure you and your family have been through quite a lot. It sounds like you are on the right path in taking steps to understanding what is going on now that you have a name for his issues. You will find lots of support here. You may go through a lot of emotions as you come to terms with a diagnosis. On one hand it's a relief to know that there really is something mentally going on with your husband. On the other hand as you read about BPD you may get upset knowing that he may never be able to get better. When I realized what was going on with my H I went through all the stages of grief.
We have a lot of lessons on the right side of the page. THis would be a good place to start learning more about BPD, about how to communicate with your pwBPD better, and how to take care of yourself and your family.
Here is a link to one of our lessons on Supporting your PW BPD:
https://bpdfamily.com/message_board/index.php?topic=106134.0