It's a bizarre feeling when you get to the end of a huge series you've been really invested in. I read The Baroque Cycle (Neal Stephenson) in my early twenties and when I got to the last 40 pages or so, I started rationing them out, because I wasn't ready for it to end. Then when it ends, it's almost like a pleasant version of grief. But once you've been so invested in a book series that you feel like this, it means you've got an addiction. A healthy addiction that you can indulge again and again. I haven't ready the inheritance cycle, but Half a King is a lovely little book of a similar type that I could highly recommend.
I just meant that once you've got hooked on one big book series, you will find yourself craving another series, just like an addiction. But it's a healthy addiction, so you can indulge that addiction as much as you like :)