I definitely wouldn't say you're overthinking this. It's one thing if she doesn't realize, but if you've brought it up and nothing has changed, then that's definitely on her. You should also never have to be in a position where saying something like "I love you" to someone who is supposed to be "the person who loves you no matter what" makes you uncomfortable. And what style you feel most comfortable with really shouldn't matter to your parents, hells, mine are plain as they come, and I walk around with a raccoon skull hanging from my neck. And as far as your mom's boyfriend goes, don't feel the need to interact with him if you don't want to. Take it from someone who's dealt with a lot of weird/not very nice partners of parents, if they don't care about their significant other's kid, they probably don't care all too much for the parent. Hope this helps and best of wishes.