I remember that we felt the same way while waiting for our coach to be built. There were days we wondered "what the heck were we thinking???" That was in late 2012 and were new to RV'ing, never having camped nor driven anything bigger than a Honda.
Now we are on our second, but larger coach and full timing!
Looking back, I wish I had relaxed a little but the worry of the unknown made us prepare and educate ourselves to be safe and secure. We took a driving and other courses, read all the material we could and learned from the experience of others on the forums. I did have to remind myself that most of the forum posts have to do with problems encountered and not the everyday enjoyment of RV'ing.
A little worry is helpful and OK, and all will be well. Enjoy the adventure ahead!
Paul, Kathy, and Tux a 4 month Mini Schnauzer
2014 Tiffin Phaeton 42 LH, 2013 Honda CRV
"When the time comes to look back, make sure you'll like what you see"