A mix of things helped me whenever I felt demotived.
1 - Really helps to have a “why”. Why are you learning Japanese? What reasons? It doesn’t have to be anything spectacular, and you don’t have to share it, but having a core reason can help give more purpose to your studies. And of course, that reason can change over time too, just keep it in mind. Maybe write it down and post it where you’ll see it often.
2 - Seeing results in real life. WK stats are great and all, but they don’t always push you. What helped me a lot was having my favorite manga in Japanese by my side, and constantly checking it each time I leveled up. What new kanji or words would I be able to recognize? How much more would I be able to read? Actually seeing the improvements outside of WK made a huge difference for me.
3 - Sharing your progress or finding a partner can help. Having someone by your side, even if they’re not learning Japanese, but perhaps another language or venture, can be helpful. You’ll keep doing your best and they’ll keep doing their best. You can occasionally check in, give each other tips, advice, or just cheer each other on when needed.
4 - Italki/HelloTalk or a services like them. Talking with native speakers is like #2, where you get to see your results manifest in real life. Not only do you get to utilize your kanji knowledge, you get to communicate with native speakers and learn from them, growing your knowledge bank even more. These services are meant for any level, even if you know nothing at all, so don’t feel abashed on starting sooner than you feel ready for.
5 - Goal setting with time limits have helped me too. Like the JLPT for example. It gave me a date and assignment to work towards, and once I dropped the money for it, might as well try to go for it. Regardless if I pass, it’s another fire under my butt. These don’t have to be big goals though. Like @fcc323 mentioned, short ones can work great too! I use those a lot as well
I guess you could also go over your thoughts when you think about studying. If you load up WK, what goes through your mind? Maybe analyze those thoughts and figure out what’s stopping you. From there you can start to tinker with it.
Hope those ideas help! You’re definitely not alone in the struggle, but you’re also not alone in the support! We’re all cheering for ya’ Good luck!