I, personally, simply have a low tolerance for repetition. It wasn't bad when studio time was relatively expensive and projects I was involved with tended to be resolved
relatively quickly.
But when I set up my own project studio and began charging the rates you could get for a graymarket studio at the time, people started spending a lot more time on things and I felt myself burning out as I heard the same works over and over.
Also, like many artists who drill into a pet project, I could drive my
own projects into the ground because of compulsive twiddling and retwiddling.
I'm afraid I took the nuclear option on the first situation (went back to the day job, which made better economic sense at a time when my personal economy was beginning to look threatened [and boy was I right, there

])... and on the second, I made a point of working on quick, simple projects for a while until I started liking my
own music again.
Obviously, you probably want to avoid a career-change. So I suggest getting out and seeing live music you
really like -- not bands you think you could pick up as clients -- and take up the suggestion above to find some new, fresh (you should pardon such a stale word) music that you can get genuinely enthused by.
I'm a
genuinely old guy, and am pretty damn crotchety about the state of mainstream pop music -- but if you look around, there is a lot of really
good stuff from artist/bands that
aren't looking to throw themselves into The Big Cookie Cutter that generates so much radio and TV musical content these days.
(Now,
me, I got
caught up in the whole RE-identity thing for a while, and I've
always loved tape machines and recording, since the first one I saw, before I even knew such a thing existed, when I was "candid mic"-ed into performing my big hit of the era, "Mary Had a Little Lamb," a capella. I was about 3-1/2 or 4. It was
a moment. But when I got back into recording seriously, went to school, then went to work freelancing, my
initial impulse had simply been to get recording time for my band. But the band broke up during my first full semester of school and the rest was boring personal history.)