Your nervousness isn't a terrible thing as it puts you on high alert. It is a sign of caring and responsibility. There are so many guys that go out there and just do whatever, the consequences be what they may. Dealing with the excess nervousness is a progressive thing. Some folks, like me, never get 100% over the nerves when flying, but as you build confidence you'll be able to do more and more advanced flight maneuvers.
As noted above, take things really slow at first. Most humans only have experience driving cars so only know forward and backward and turning on an arc- and on one plane. A UAV not only also does that but goes up and down, side to side and can do them all simultaneously. It will take some training and practice to get it all down. Baby steps, each time pushing your envelope just a little more as your skill develops will help with confidence even it it doesn't completely calm the nerves. But you'll see that at some point in a short while you'll only be slightly nervous doing the things that turn you into a puddle of jello today.
One thing that we all have to learn to accept is that one day you will crash. But your care will keep the crashes and the damage to a minimum. Learning to understand that crashes are ultimately inevitable is hard, but with caution will also help tamp down the nerves.
I have attached a video below that might help you. Good training for control and confidence as you prepare to further spread your wings.
