Rant about my roommate sharing room with me, his girlfriend and one more guy who mostly stays

I moved into a two-sharing room in a 3BHK apartment in Bangalore six months ago. At the time, I wasn’t informed that my roommate’s girlfriend would also be staying with us. On top of that, one of her friends (a guy who is a mutual friend of theirs) is almost always at the apartment too, except for sleeping. This means I am effectively sharing the room with three other people, even though I’m paying for a two-sharing space. The rent and other expenses are split only between me and my roommate, which felt unfair. Initially, I didn’t mind the lack of personal space too much, especially since my roommate is considerate and doesn’t disturb me while I study. However, constantly feeling like I’m being watched made me increasingly uncomfortable. After four months, I decided to address this and shared that I didn’t like sharing the room with so many people. It’s frustrating because I wasn’t informed about this arrangement before moving in, and now, shifting to another place would be costly. When I brought it up, the girl claimed I couldn’t expect privacy in a shared room. This annoyed me because she isn’t even contributing to the rent and is essentially staying for free. Following this, I told my roommate that I didn’t want her in the room anymore. My roommate responded in a gentle tone, saying the girl doesn’t use my bed or cupboard, and since she’s a friend, she won’t pay rent. I tried explaining that there’s a big difference between a friend visiting occasionally and someone living in the space. Unfortunately, I can’t move out right now since I’ll need to relocate again in six months. Apart from my roommate, I don’t interact with the others. What should I do? I get a feeling that they do understand my situation but they can't stop coming as they don't have other place like this to meet. It would be good if I make friends with them as it's 6 months I have to stay here and they are not bad people. Just that my energy doesn't match theirs.