being the introvert in a group of extroverts

I am an introvert. I am quiet. I am shy. I am not outgoing. This is all magnified in situations with new people. They started a new young adult bible study at church, and although I do know some of the people there are still a lot of new people. The past couple of weeks I have felt frustrated with the bible study. I feel this pressure to share and participate more in the discussion. My learning style is more quiet. I listen pretty well, and it takes me longer than most to process the information. So I often don't have a quick response to a question, because I am still thinking. It also just takes me longer than most to feel comfortable even in more social situations. I choose my words carefully. I think a lot about what I feel comfortable sharing with people, even my close friends. It's not that I am secretive with my personal life, because I'll share personal things. I am happy to share joyous moments in my life. I know I'll feel better and closer to people when I share my struggles and the sad moments in my life. However, whether it be something joyous or sad, I won't share until I am ready. The whole situation makes me miss my friends from college. I miss how easy it was to talk and share with them. I miss how close we all are. I have friends here at home, but I am not as close to them. I try to remind myself that we didn't get so close over night. It definitely was easier to get close to them when we didn't have as many responsibilities and we lived together. I pray that next time I feel more comfortable and that I can open up during discussion.