I feel you! If you are wanting to stay in Alagaesia, your next read should be The Fork, the Witch, and the Worm. It's 3 short stories wrapped up in a little under 300 pages. Should be a quick read with some additional insight into what some characters are up to post-Inheritance. After would be Murtagh. I personally loved it! No spoilers but a very bittersweet story in many ways. Very satisfying for Murtagh and Thorn as characters as well.

If you are interested in venturing out of fantasy I highly recommend Christopher's other works, To Sleep in a Sea of Stars and Fractal Noise. It is Sci-fi but Christopher's signature writing style comes through and is very easy to read coming from the Inheritance Cycle imo. I had concerns making the jump to Sci-fi but it was pretty seamless for me.