Hey i feel bad but really fear is an illusion. You have to understand we are all one - the same - all humans. Every single one of us has the same fears and really we dont even need them. We can allow them to be there, and let them go. Simply accept that you are fearful because it is not WRONG or BAD to feel these feelings - it simply is. Allow them and let them subside: rule number 1 whatever you resist persists. Just allow yourself to feel it in this moment, become aware of it, don't judge it or label it as bad. And take a deep breath, step outside your room:
See the first person and say "hey, can i join in?"
Thats it. Trust the process.