My dog was reactive towards a kid

Please be kind . I already feel like shit.

I have an almost 4 yo mixed dog . I love her but today I brought her to my 1 yo nephew party and there was a 6 yo kid. I didn’t know the kid was going to be there. I kept the dog and the kid separate in different rooms for most of the day but at the end of the party everyone went to say bye and my dog got reactive towards the kid. I think my dog almost bit the kid . I separated them immediately. My dad says my dog only barked at the kid while I sure she almost bit her. I never bring my dog to parties because it causes me too much anxiety when there are kids around. I don’t think I will ever take her again but I am now worried about my nephew. Most of the year I manage by separating the two , not bringing my dog to family gatherings. But during Christmas and some week in the summer we all go to the cabin and every year it’s an anxiety induced time . I wasn’t worried too much last year because he was not walking at all but now that he is starting to move around I am terrified something might happen. It’s a constant fight with my family because no one believes me that she could bite even if she never has.

I feel terrible, I feel like I am disgusted by my dog and mad at her and myself and worried to my stomach about the situation. It makes me feel sad and angry. I love my dog but I wish I never had her due to these kind of situations.

I needed to talk to someone who could understand what I am feeling .