It can be tough to stay motivated - this is a long term project, and meanwhile real life is going on around you. I push through by going slow when I feel overwhelmed (limiting my number of lessons, trying to stay under a certain number of apprentice items, etc). When work and school and family and life and all the things pile on - I’ll simply turn on vacation mode and set a date to turn it off again (this is strictly use at your own risk/need, and many would advise against it, so play responsibly).
But that’s just how I push through when I’m feeling unmotivated. I keep motivation up by 1) diversifying my studies and 2) reading fun material. Diversifying a bit helps to break up the monotony of reviews and lessons. It also helps to speed up my reading progress since knowing a bunch of kanji and vocab is not enough for comprehension in most cases - a certain amount of grammar is needed as well. And reading material both shows me all the progress I’ve made and reminds me why I’m doing this in the first place - to consume native material in its original form. Sitting back and just enjoying an anime (still with English subtitles ) helps, too.
I have the added bonus of having a study partner - my lovely husband keeps me on my toes. I have to maintain my ten level lead on him!