Girlfriend [23F] is starting to take over my [25M] entire life

We started dating around October of last year and things have already accelerated quickly. At first I've been fine with going kinda fast since nothing was interfering with my work and personal life, but in the past month things have gotten out of my control completely.

Until a month or two ago, we would only really see each other on weekends, but then she started staying over during the week, sometimes wanting to stay at my apartment when I wasn't there. That's cool, she's been at my place many times. Now we've decided that she's going to move into my apartment, which I'm also okay with, since I figured it would give us more time together and make our lives easier. She's started bringing her stuff over and we've made room to place it all together, and that was all fine. I figured as long as we're making decisions about our apartment together, it'll work out and we'll both be happy.

Fast forward to this week: I had to go on a business trip out of state for the entire week. Without asking ahead of time or even bringing up the idea, apparently she invited her friends to come to "our" place since I wasn't going to be there. It wasn't until they already agreed to go that she told me she invited them. I've only met these friends twice ever, so I don't really know them. I made it clear that I wanted to have friends over for the first time when we're both there, since it's our apartment, not just mine or just hers. I made it clear that if she's going to have people over I don't know that well, I'd at the very least like a heads up. She seemed to agree that was fair and said she would.

Today, I barely heard from her at all and sent some texts to see what she was up to. Turned out she was busy moving stuff (including some of my things) in "our" place around, and decided to invite even more friends over than I was told about previously. Less than a week later and she's repeated the exact thing we agreed not to do. But I played it cool and didn't mention it since her friends were already over.

There are other similar things that have been going on that I didn't really mention, such as changing where some of my personal (definitely not shared) hobbies are in the apartment, changing sleep/eating schedules, and a recent overall lack of communication when it comes to doing things that affect either our relationship. But this scenario really did it for me, since this used to be my personal space, my comfort zone, and it feels like within a 2 week turnaround it's like it became not "our" apartment but "her" apartment. Even when I first brought up why I was asking for heads up about inviting people I don't really know without me there, she seemed like she understood where I was coming from and that it was a reasonable request.

The advice I'm looking for is pretty simple. Am I overthinking this? Is this not as big of a deal as I'm making it to be? If this is something to consider, what's the next step I should take? She can't move back to her old place and it would be pretty much impossible for her to find somewhere else, so we definitely will keep living together. But if these surprises keep happening and there continues to be a lack of respect and certainty, especially when we've discussed it and agreed to it, I'm not going to be able to stand it for very long.

TL;DR: Recent girlfriend is moving into my apartment, and I already starting to move things and invite people I don't know well, despite us discussing that we should keep each other in the loop.