I have BPD and bipolar type I comorbidly, and I just started on a new antidepressant a few days ago. I'm having a few adjustment issues (side-effects which I hope will wear off), and one side-effect that's hitting me particularly hard is extremely vivid dreams/nightmares. One of which I had last night which left me feeling sick and guilty all day until I finally decided to talk to my wife about it. 

I told her about the dream, which was roughly as follows: She had been going out to 'concerts' a few nights a week, and as she left to go to another, I asked her who she was going to see. She gave me a name, and I pointed out that she had said she was going to that concert last time, as well. I suddenly knew (in that dream-certainty way) that she was cheating on me, and when she didn't deny it and refused to tell me where she was really going, I got furious and told her that I didn't love her any more and just walked away with the dream-certain feeling that it was over forever. 

Then, as soon as I woke up, I was hit by an abundance of guilt and sadness that stayed with me all day until I was compelled to 'confess' the dream to my wife. She listened calmly and then merely said "hmm." I asked "hmm?" and she said "Nothing. Just funny that you were so quick to decide you don't love me." 

In that moment, all of the rage and hurt came flooding back, and my instinct was to yell at her that she was the one who cheated in the dream and that I was just reacting to that. But instead, I mentally took a step back and physically removed myself for a bit to cool down and de-catastrophize. 

A few minutes later, I approached her again and said, as calmly and neutrally as possible (and probably not quite as eloquently as follows! This is just the points I covered in what was likely a rambly mess), "It was a nightmare that played on my worst fears, not how I really feel. I know that you aren't cheating on me, but it is one of the worst things my brain can think of to throw at me in a nightmare. In the dream, I was splitting - I reacted to you cheating by going completely cold and turning against you. It's not in any way reflective of how I really feel, and I would like to be able to talk to you about my vivid dreams with the understanding that they don't reflect reality in any way other than playing on my fear of abandonment." 

She felt bad about how she'd reacted and assured me that it was okay and that she knows I don't hate her and that dreams can be awful things. I apologised for upsetting her and reiterated that I wanted to talk to her about it because I do love and trust her. And then we were totally cool. 

I was pretty proud of myself for stepping back instead of letting it escalate over something as silly as a dream. And my wife is awesome, too. I don't blame her for being initially stung by knowing I a dream I had like that about her and us. We've been together 16 years, married almost 5. I know I can be a little difficult to live with, despite the huge strides I've made through therapy and personal mindfulness application... but our good times vastly outnumber the bad and I'm really lucky to have someone like her in my life.