Definitely the AH, she doesn't deserve what you put her through.

You need to grow up. No matter what anyone's opinion is, you either have to not let people's opinions bother you. Or you let them bother you so much, that you tell them to shut their mouths about someone you claim to love.

Idgaf who opens their mouth, if you are talking poorly about my partner I will tell you EXACTLY what I think of you. Could be my mother, father, or best friend. I see you and your flaws and I will start a fight. Watch how you talk about my person.

Your partner, ideally, is your person, the one who has your back and you have theirs.

If you can't do that for someone, genuinely, don't bother getting in a relationship.