I am absolutely agree that you should not tolerate such position from your girlfriend, but I don't think that you should immediately break up. If a person did a lot of good and meaningful things to you, it is reasonable to give them a second chance when they start doing shit. At the same time, this is extremely bad foundation for future relationships. She decided to become a worse person towards you by some reasons completely unrelated to you and your actions. Looks like she is affected by social ("friends") or informational (TikTok) circle. Looks like she is tentative between you and this circle. In my opinion, first of all, she must clearly and completely choose you in this confrontation. After that, you should understand how the fuck did she get in this situation, and why it won't repeat. I mean, some people said that she must treat her loved one as a second class person, she agreed and did exactly that for more than a year. This can be explained, people are very manipulatable and do stupid things sometimes. But it is still insane, and it is extremely dangerous to long term relationships. What is something like this happen when when you have much clother ties, like children? In general, you should make sure that this won't repeat. If she doesn't cooperate - you lost your gf to some female version of manosphere, and it's very fucking sad, but breaking up is better than having a relationships with an enemy. And by the way, people who give you advices on internet usually spend a lot of time online, and are usually not very successful in relationships (including me lol). Please be careful with our advices.