Intelligent people are INTENSELY OBSERVANT. They can literally see right through people: their intentions, their animosity, and their lies. That's why they don't entertain performative energy, they live a quiet life & mind their own business.
The fact that you can now see how your response may have landed is an important step. Insight is valuable. But remember this: insight doesn't erase impact.
Many people believe relationships end because someone stopped loving. More often, they end because someone stopped feeling understood. When a partner is hurting, they're rarely asking you to solve the problem. They're asking, 'Do you see my pain? Does my pain matter to you?' If your first instinct is to explain, analyze, or defend, they often hear, 'Your feelings aren't important enough for me to stay with them.
Your calmness wasn't necessarily the problem. The problem was timing. Logic has a place, but not before empathy. People don't usually absorb explanations until they've first felt emotionally safe.
If you decide to speak with her, don't make your goal reconciliation. Make your goal truth. Tell her what you've learned about yourself, not what she should do with that information. Don't ask her to reconsider. Don't ask for another chance. Simply acknowledge the hurt you now understand you contributed to.
Something as simple as, 'I realize now that while I was trying to understand what happened, I failed to show you that I understood what you were feeling. I can see how lonely that must have been for you. I'm sorry,' carries far more weight than a long explanation.
And one final thought: if your apology creates pressure for her to comfort you, forgive you immediately, or reopen the relationship, it's no longer an apology, it's a negotiation. A genuine apology gives the other person freedom. It says, 'Whether or not this changes anything between us, you deserved better from me in that moment.
Sometimes the greatest act of love isn't convincing someone to come back. It's becoming the kind of person who would have loved them better, whether they return or not. That growth is never wasted.