N.A.
I had the same problem at work. I had a ...well still have...a terrible boss so it took me a while to learn that it wasn't just me she was mistreating, it was everyone. So little by little I broke out of my shell and as people go to know me they liked me. I do tend to keep to myself, and yes a lot of people say hi one day and not the next, but I take it with a grain of salt. I try to look at how I'm acting around them too. It does feel like high school a lot so I just try not to say anything that I wouldn't want repeated to someone else. It takes a while to learn who to trust and who not to. It took me a while to feel like I fit in at work and it's taken some time and effort but I feel like I do more so then when I first started.