Plz tell me if I'm overreacting?!

My mom has been seeing this guy for less than a month and already moved him in with her. I was extremely uncomfortable about it. I've met him and he didn't seem like a bad guy. Just felt everything was happening really quickly. My kids went over my mom's house after day camp. My 15 year old son has epilepsy and tends to have seizures. He had a seizure at my mom's house and sometimes his seizures cause amnesia. My daughter called me because he had a pretty bad seizure and lost like 10 years or so of his memory because he was behaving like a 5 year old and was scared and crying. Especially since he didn't recognize my mom's boyfriend. Instead of helping him he was recording him making fun of the situation and put it on TikTok. When I found out he did take it down but I went tf off! My mom told me I'm overreacting and he didn't hurt my son. He didn't help him either. He was terrified and he basically mocked him to put it online. Her boyfriend defended himself saying he has like 10 followers and he just thought the situation was funny and it's not like he recorded the actual seizure. I honestly don't care. I told my mom my kids won't be back over here around him if he can't understand why I'm pissed. She said that's fine and she's not dealing with me and my overreaction and if I can't respect her boyfriend she doesn't want me or my kids around. Am I really being dramatic?