I'm sorry to say this but yes, this is a really bad situation. My experience of the majority of chinese students is they form a clique with each other and will not make any attempt to include you, they're not being spiteful, it is just how most of them are coming from such a different culture.
I had a similar situation in first year, my flat was all international and they were all second / third years. It was a huge mistake to stay there and not transfer to different accomodation because it was a miserable dead flat and I ended up eating dinner alone most nights as the internationals were ghosts that never left their room.
If I was you I would try your absolute hardest to mix with other flats ASAP and contact your accomodation office to say you are not happy with this situation, the faster you do this the better, they may be able to move you quickly before everyone has settled. After first term it would be much harder to move flat and settle in.
Whatever happens though don't be one of those people that drops out altogether because they have a bad flat. Im in 4th year now and although my 1st year flat was rough, I made the best of it and had good friends, then by 2nd year I had a great house with those friends and a big social circle.