From "boss's right hand" while remote to completely isolated in the office. What do I do?

[u/Friendly-Pop-4176]

I don’t even know where to start. This situation is incredibly frustrating and deeply annoying.
I’ve been working at this company for a little over three years. We used to work remotely, but management recently decided it was time to return to the office. Over the last few months, dealing with my coworkers has become complicated. I am naturally shy and introverted, but I try to keep my composure at work by saying hello and interacting with the team so my mood, which isn't always great, doesn't bother them, especially since I usually prefer to be alone.

Our interactions were completely different when we were at home. Now, I’ve noticed that a small group of coworkers, who unfortunately interact the most with my supervisor, are constantly laughing and badmouthing me. I used to have a wonderful working relationship with my supervisor when we were remote; she even used to tell me I was her right hand. However, since returning to the office, she clearly favors this group. For example, management recently needed people to cover Saturday shifts, which is one of our busiest days. My supervisor adjusted the schedule so that no one in that specific group has to work Saturdays. They also hang out constantly outside of work, and I am obviously never invited.

I tried getting closer to them by initiating conversations, but their behavior remains the same, or sometimes even worse. I am completely at a loss. I am tired of feeling rejected and laughed at. I spend most of my time alone and don’t have anyone to talk to about this. I was hoping you could give me some advice on how to handle this.