What's the Difference Between Fellowship and Mission?

What gives me energy and hope is something that I've really struggled with for years. And that is, I need to know the difference between when I'm in fellowship with people or when I'm actually trying to witness to or be a missionary for. If I'm not clear about where I am and who I'm with, it is so paralyzing to me. As long as I know there's still, I have brothers and sisters that are serving with me that can build me up and I can build up. Then we can go out into the world and share goodness with them.