when I get tired of fashion, I just drift into a "uniform" routine- sweater, jeans, and ankleboots, or buttondown, jeans and low sandals, as the case may be - but I've such a habit of doing my hair and makeup, I can't not do it.
I find that if I go in fashion "autopilot" long enough, I begin to have enough distance to start fasion again with renewed interset.
what you ought to do is figure out some nice uniforms for yourself, that look good, are always appropriate, and you dont have to think about. Then you'll look good until you no longer feel fashion overload, and have renewed interest.