I did this process twice, with many months in between. The first time, my dream portfolio looked like yours with a lot of different kinds of artwork. What finally helped me was this:
What 5 artworks from other artists look the way I want my artwork to look just for the next long-term project I'm working on, AND I can replicate the feel of them using mediums I know well? Each image had to meet both requirements.
Gone was anything I knew I couldn't do without many years of study, and gone was everything that I enjoyed looking at but wasn't exactly precisely how I want my project to look when finished. It helped me to use only a few images instead of a bunch. Also, because I realized I can't find anything exactly like what I want to create, I used 3 full images that represented the overall feel / colors / composition etc, and 2 images that I cropped very narrowly to show the way I want to draw my characters.
Next, I added 3 pieces of my own drawings (also cropped to show a specific part) which I felt got the closest to my goal for my project. I made a collage of the other artists' work touching my own (no spaces just one big image). I immediately noticed where I was headed, what about my work was wrong, what about my work I liked better than the other artists' - lots of insights. I put this image as my desktop background to see every day an idealized version or symbol of the kind of work I want to do.
I am a fellow fan of Miyazaki's work too 