I find practicing a lot helps me. If I am unprepared I think a lot, get flustered and run into trouble. I find i prep 2-3x more than my colleagues at the moment. A second thing I do is doing a bit of mindfulness. Why do I feel anxious? Is this feeling rational? What am I actually going to be doing? Is it as hard as I think it is? Is there anything that could make this easier for me? What is the worst thing that could happen? I find spending 10-15 minutes doing this helps the logical side of me smooth the emotional irrational side and set me up for success.