I respectfully disagree. Your identity is formed from the values and principles you firmly believe in. Others are changing, and you cannot form an fixed identity and character on something changing.

It is OK if you feel that you really want to fit in but cannot. It means there is a challenge. Address it directly. Life is full of opportunities. Prepare for the next one. The important thing is that don't isolate yourself completely. For now, I suggest just to keep it formal and at the surface, and focus on your duties in your job, no matter how trivial they are. Just do them. Greet your colleagues when encountering them accidentally, and chat if you feel it is a convenient time for a chat for both of you. Try not to feel the obligation to talk to and participate in social gatherings.