Splitimage: Maybe this new type of environment is the better one for you. Being able to shut yourself away in a larger corporate setting was contributing to the problems you had originally. Not necessarily caused them, but might have contributed to them. Being in a smaller, more open environment could help to keep other problems from re-surfacing. It might be a wonderful environment to be included in discussions and usually smaller groups share the loads more. At least that was my experience with small groups.

I am sure you will be great, but don't expect too much of yourself to start. We often are our own worst enemies expecting more of ourselves than the coworkers do.