I won’t reiterate what others have said before, except that I validate how you feel.
I started this summer with similar goals in mind. It was easy at first because I had the whole summer to devote to study. I was absorbing information at a staggering rate. SRS honestly was the bane of my existence then too because I just wanted to keep building momentum. Now that the school year has begun, I have less free time. I do all my Japanese podcast listening in the car because I have very little time otherwise. I will keep up with WK and other things, but I have had to scale back everything because I didn’t want to overload myself, and some days I don’t have the mental energy to study intensely. I sometimes have to remind myself on busy days that–if I spoke any Japanese that day, if I thought sentences in Japanese, if I opened up a book or an app and did review–I’m still making progress. It’s just slower.
You might consider looking for a new resource that excites you and refreshes your interest in studying Japanese. Maybe even replace that with something else that is proving less beneficial to you at this point in your studies.
You’re also in the thick of it. I recently saw someone else post a timeline with the volume of stuff that comes your way in WK, and level 38 is about at the thickest section of it. If you keep going, you will probably see the load start to lighten. But also if you need a break from WK and are terrified of coming back to 1000+ reviews, you can activate vacation mode.