First of all -- I'm really proud of you for tackling that situation. It is a massive peeve of mine. As a person who has been engrossed in disability their entire life (family, friends, careers, even myself) it so often told 'wrong.' I can't tell you how many times I've had to sit with my own mother, myself, and other parents and help them through exactly that.
The fact that it is taxing is something that I take as a good sign. I means you care. You're trying to hit the right notes and beats.
And, yes, omfg, yes. I had this happen to me the other night. I was writing an emotional scene between to characters, and I had no intention of having this one line of dialogue hit as hard as it did. It broke me. I had every intention to keep writing, but I sat there staring at it for twenty minutes.
I couldn't get out of it. I needed to stew and to brew. It's kind of like a cry. It's done when it's done. You just gotta get it out.
Though, when in doubt: go for a walk, even if it's just around my house.