Hugs to you. It happens to me as well. They just don't get it. I have tried everything short of performing circus acts to help them understand and they are clueless. Ultimately they say those awful four words.
Triggers! and it is like yesterday. There is no such thing as space of time I am right back there. Sometimes it is agony.

It happened to me this weekend with a family member. We hadn't spoken in six months and she contacted me I was courteous and polite. After the convo I wanted to just die. And the other person ...

I suppose they felt it gave them license to invade my safe space. I had to totally separate myself or the abuse would do me in. Two emails since in a 24 hour period. I just want them to leave me alone. They have done enough damage. I will never just get over it and it does matter
Big hugs to you