I have been married for 10 years. It helps that my spouse is willing to listen and support me when my emotions are raw, but not try to "fix" me. He also knows when he's not the right person to help.
We've both had traumatic experiences as kids and as adults, so he understands when things come up for me, and vice versa.
I've had a lot of relationships that blew up because of my BPD symptoms. For me it helps to know that "falling in love" is highly addictive, and I needed to start relationships off as friendships first.