How do I heal my relationship?

There's many layers to this question that I want you to consider.

1. To get proper techniques, you will need to actually get into treatment and talk with a therapist more in-depth.  When you're ready, set yourself up with a therapist and start that process right away.

2. What kind of verbal dispute was this?  And why did things escalate to the point of you using her past experiences against her?  What were her past experiences and situations that you mentioned?  What pushed you to that point?  What did she say or do that made you feel that the only way to "win the dispute" was to go there with her?

3. How often do the two of you argue?  How often do those arguments go unresolved?  What do your arguments consist of (content)?  What do you believe is underneath your arguments, what is not being said?

I preface this by saying, again, that counseling will definitely help to get under a lot of the issues you're having.  Many times arguments derail because of ego and pride.  When someone says something that triggers the other person, s/he gets defensive and says something to wound the other and end the conversation.  Rather than seeking to understand and resolve conflict, we instead go for the jugular and try to overtake the conversation, treating it more like a game to be won (adversarial) rather than a problem to be solved (partnership).  So we end up saying things we know will upset the other person and get them to back off instead of swallowing our pride and listening to what the other person is saying.  We have to remember that communication involves listening, really listening, to the other person.  We cannot enter conversations ready to defend turf.  We only end up shutting down and utilizing defensive tactics to get the other person to stop talking.

Do you feel safe to communicate?  Does your partner feel safe to communicate?  Before the two of you try to have a difficult conversation again, I think it would be wise to discuss this issue of safety in conversation.  What are you doing to make her feel unsafe?  What is she doing that makes you feel unsafe?  If you can understand that, then you can begin to work out how to talk to each other without denigrating each other.

Hope this helps!