Thanks for writing!
Your story is quite amazing. I agree with Diana that it's most likely that the anger you felt toward the man who spoke about your father is the most likely cause.
Is there any particular stress due to winning the car? Are there large taxes to be paid? That could play a role. And sometimes our brains can confuse excitement with fear, since they are quite similar in many ways.
In any case, I suggest that you do some writing about these issues. Allow yourself to be angry at the person and then let it go. Imagine punching him in the face and then walking away. Then take deep breaths and let all of the anger go. Breathe in peace and breathe in compassion for yourself and your father.
Know that whatever the cause (and we often really don't know what triggers TMS), this is definitely TMS and you will be fine. TMS occurs; it happens to me too, even though I teach others how to recover from it.
Does this help?