Did I overreact when my girlfriend playfully hit me in front of her friends?

I'm feeling really confused and could use some advice. My girlfriend (22F) playfully hit me (22M) in front of her friends after I teased her a bit. Last night, she hosted a birthday party with all her friends, and it was a blast. She's a huge fan of a goofy movie, and we've always joked about her obsession with it. While we were hanging out, I was making fun of the movie, and she playfully punched my shoulder. It didn't hurt at all, but her friend next to her looked shocked and waved her off afterward. I understand it was meant in good fun, but I find it disrespectful to be hit, even playfully, especially in front of others. I grew up in a loving household where my parents never laid a hand on each other, even in jest, and they taught us that physical reactions aren’t acceptable, regardless of the intent. The rest of the night, I felt a bit off, and after her friends left, she noticed something was bothering me. I told her I was surprised by her hitting me; while it didn’t hurt, it just felt off and disrespectful towards a partner. She ended up having a breakdown and felt terrible about it, which was really upsetting. She said it was completely inexcusable, especially given all the things I do for her in our relationship. To add some context: I do put a lot into our relationship, and while I'm happy to support her, I get frustrated when she’s late to things. After all I did to help her prepare for the party, it felt inconsiderate to be hit, even playfully. She really panicked and said she feels like she gives so much less in this relationship and that she's overwhelmed with school. She expressed doubts about why I treat her so well and doesn't feel like she’s "girlfriend material" for me. Honestly, I wasn't that upset about the incident; it just bothered me and felt slightly disrespectful. I’m not angry at all, but her extreme reaction and guilt make me question whether I have the right to feel this way. Our relationship is typically filled with love and affection, and I’m fully committed to her. It just hurts to see her so upset, especially when I didn't do anything wrong.