“My coworkers make me feel like an outcast”

I started a new job and, unbeknown to me, there were two distinct social groups. I did not try or intend to, but I fell in with one group. It soon dawned on me that the two groups had an almost visceral dislike for each other.

Six months later, and within the space of a month, all the people from my group had quit or moved on to other positions. They were replaced by people who formed friendships with the second group. This has now left me alone and feeling somewhat of an outcast from the newly formed much larger single group. For reasons I won’t go into I cannot quit this job, as much as I would like to. I don’t know what I can do.

It is horrible, nobody talks to me and I am rebuffed whenever I try to engage with anyone. I feel stupid for saying this but I even feel I am being actively bullied by some members of the new group.  Thank you, any advice will be welcome.