Chemistry should be respected but not feared.
This should be carved in stone, and the resulting plate exposed... well, everywhere.
That said, the problem pointe out by the OP sounds quite normal; I'm a theory freak too, and it got a lot to feel comfortable in the lab. You just have to do three things: practice, practice and practice.
And remember to breath deeply, every now and then
. Slowly, you'll start to become more and more confident.
Always trust yourself. Your solid, hard-learned theory will be invaluable in the lab.