How do I implement constructive conflict resolution in my marriage?
I love your question, and your openness in asking this question! You showed humility and vulnerability in being able to ask this and to share your feedback from your wife about her feeling of the intensity and that she is made to feel small. I sense that you don't want to make her feel intimidated or less than, and hence you are looking for answers to make this better.
I would like to help you to find this answer within yourself, because I truly believe that it is there within you. You wrote about how your wife feels. Are you curious about what that feeling is like for her? I think that maybe you are, and that is the key. Of course if there is a conflict, there are two sides to it. Both of you want to be heard, and both of you want your own needs to be met. What would happen if you put your curiosity about what your partner needs first? Seek to understand before seeking to be understood. We can't hear each other when we are busy trying to make them hear us.
Part of that curiosity is setting aside your reactions to your partner's needs or wants and validating her emotions. She feels what she feels, and there is a reason for that. It is not a judgement on you or on her. Emotions just are. You each choose what you do or say, but you feel what you feel. Is it possible that the conflict in question might not even be as important in the grand scheme of things as creating the safety of being able to feel and share those emotions and connect with each other in the safe space of your relationship?
Your question is about how to implement constructive problem solving. The words that you say will follow from your attitude of curiosity without judgement.
If there is already hurt and conflict between you, there may be some steps that need to be taken before you have this safe space where emotions can be shared. Maybe you need to take a time out and use the time to regulate your own emotions before coming back to re-engage in the conversation.
Is it possible that any of the "Four Horsemen of the Apocalypse" are at work? Curiosity is an effective antidote for the four horsemen too. For more on this, I will refer you to the Gottman Institute:
The four horsemen are criticism, contempt, defensiveness, and stonewalling. These guys can wreck a relationship if they are not put in check. The article that I linked to above discusses them and the specific antidote to each of them.
Once you have created a safe atmosphere where both of you can express your needs and emotions, you can proceed with addressing the conflict. Remember that you can always go back to listening with curiosity, taking a time out if you need to, and recognizing those horsemen if they show up. When it is your turn to discuss your concern with your partner, there are also steps that can be helpful. A great model for that is the DEAR MAN acronym from DBT therapy. You can find a lot more about that if you do a search. I will explain it briefly here.
D - Describe the situation, briefly, sticking to the facts.
E - Express your emotions, using "I" statements. ("I feel ___." The blank is an emotion, not a place to interpret or give opinions).
A - Assert or ask for what you need.
R - Reinforce (which could also be reward or reciprocate). This is the part where you think about what your partner needs and how you can work together to find a solution that works for both of you.
M - Mindful of your objective. What is the most important thing to you?
A - Appear confident
N - Negotiate. Remember that there are at least two sides to it!
Here is an example with further explanation:
It takes time and practice. You can do this! Also, it is okay to ask for more help and support. Changing a long-term pattern in your life doesn't happen overnight.