Yes its because you are a razor rookie (I like that term btw lol). The neck is a major trouble spot and takes a while to really get a good technique going.

My advice to you would be to start shaving your neck with the balde almose flat, as in almost no angle and increase the angle very slowly until you start comfortably cutting hairs. Also, I make my lather more slick for my neck than any other part of my face, so you may want to try that (add more water to your brush).

I use about a 30 degree angle on my whole face BUT on my neck its probably closer to 10 degrees, my neck doesnt get irritated and I dont miss hair. I have very sensitive skin as well. On the bright side at lease all you have to worry about is technique and not the edge on your razor