It sounds like, from your post, that your thoughts of finding a new job is a good path. Your current workplace does not sound like a good fit at all. I don't think I would like working there either.
I am a very introverted person and what helps me at work is making other people talk so I don't have to as much. Stay away from the big bads (Religion, Politics, Economy, etc). When I have to approach someone, I usually smile, say hi and introduce myself then ask if there is anything I can help them with. If I was in a sales job, then I would ask something along the lines of "Have you heard about such and such product? Let me tell you some more about it." If someone catches me off guard with a question (my boss loves to do this too) I usually repeat it back to them to give myself from extra time to think about it and compose myself.
I have a very extroverted guy at work who I admire for getting people to open up. He always opens up with questions that invites people to talk about themselves. People LOVE to talk about themselves.
I will sometimes script a conversation if I know I have to talk to someone important and I recite it to myself or to a friend. Also if you don't like face to face conversations, use email or phone calls if it is appropriate.
Good luck with looking for another job. Job searching really sucks, but finding a place that you don't dread going into every day is well worth it.