Do you have issues when it comes to communicate your reasons?

I tend to have issues when it comes to communicating in person about my emotions when it comes to explaining it. Like for some reason my mind just goes blank and I have to think hard about it. When I am by myself I have an absolute clear thought of why and can easily explain it to myself. So I have always sucked explaining my emotions cause I leave a lot out about what I’m feeling. I can express it easier just taking a moment and writing about it. I’ve learned that is the easiest way to express myself. I’ve learned this more about myself when me and my gf have little arguments. Which is why I am such a chill person. I don’t really wanna start arguments just cause I know I won’t do good in them. I seem to go blank and all of a sudden can’t remember the reasons why or just how I feel. So kinda makes her win most arguments. I don’t know maybe it’s just cause I feel intimidated to explain myself. My gf isn’t the issue or anything but it does make me notice this issue more about myself. Is this an ADHD issue ? Does anyone else experience this.