okay first: I love your art, and your shading is really good! <3
"I stopped liking X....and I've been enjoying X, is this okay?"
yes, ESPECIALLY if you do art primarily as a hobby, not a job. The fun part about art is there are no rules (regardless of what the internet may tell you). There are "rules" for art, but they're more like "here's the general guidelines, learn them so you know how to break them". Always follow the fun!
The biggest help in staying motivated for me is staying off social media. Even looking at art tutorials, I limit how many I watch because it can easily turn into watching 10+ videos of how someone else does it, and making no art of my own.
If you travel a lot (waiting for the bus, on planes, passenger in a car, if you know you will be in a waiting room, etc) take a pocket-sized notebook with you to doodle in, but don't put pressure on yourself to make something in it. Pick an object in the room and sketch it.
Come up with a personal project. Pick your favorite animal, and make a bunch of drawings of it playing sports. Pick out only 3 colors and finish a picture using them. Something you can make a "series" of pictures on, with a set goal in mind ("I'll make a drawing of X every week in November, as example). It's personal, so it's not a big deal if you finish, and you can always move the "deadline" if you need to.
Youtubers Proko, Marc Brunet, & Stephen Silver all have great videos on staying motivated and finding inspiration as an artist (just don't fall down a video rabbit hole ;P)