Worker at gate refused to let me measure my personal item and insisted it needed to be a carryon and to pay 75$. I understand if it’s too big but she wouldn’t even let me go measure it. She eventually let me measure my own luggage after back n forth. It is a few inches too big and she comes over and attempts to grab my suitcase out my hands and I pull it away from her. She then shuts the door of the gate and says to call the police. I then just offer to pay for the carryon and she says ok. Then refuses to use let me use my tap to pay, luckily I had my physical card on me. As soon as I walked out the door I respectfully asked for her name. She began screaming at me and threatening me. This worker was just so hostile I understand if my stuffs too big I will pay the difference I’m not trying to get over on the rules. I was confused because I was allowed to board my destination flight with this item as a personal item. So I was confused by this whole situation from the go. It also caused a massive scene at the airport and I was extremely embarrassed. It genuinely seemed like this worker was out to get me for some reason. I had literally just arrived to the gate as it was already boarding so I hadn’t done anything prior. Super weird situation and it really spooked me.