Good news - lil' Peppermint finally seems to be eating again! We tried a lot of different things but the thing that seemed to get her back into eating was putting her into a smaller cage - or, in our case, a tub. We also got a red light for her instead of a normal lightbulb but that didn't seem to change her behavior in the big 40 gallon tank she's in. The tub we have is approximately 20 gallons but it's really not meant for snake keeping lol. We may try to get her something nicer in the near future because her home is pretty make-shift and ugly now, but she ate her first meal in a long time yesterday so at least she's doing good! We've also got a proper thermometer to measure the temperature in specific spots now so that's good. We also found out that in her old cage, apparently her wooden hide somehow got infested with silverfish?? Which I can't imagine that was good for her! I don't know how they got there but we sprayed with Raid and of course are now letting it air out before we even think about putting it in her new cage. We also got a wooden log for her to be able to reach her basking spot better, but we have an even hotter basking spot in her new tub + the log doesn't fit |D oh well! I bought it from our local reptile rescue/store which also gave me free advice on what they thought could be the problem with Peppermint (surprise surprise - they were the one who suggested a smaller tank, alongside basking tho) so even if I don't use it, it still went to a good cause.
My only question is, is there any danger leaving a snake tub on the ground? This tub doesn't have an under heater btw (we have a brick that absorbs the heat from the light that's plenty hot enough) and the lamp is attached to our forty gallon lid, which is now positioned awkwardly but securely on a bin that's much too small for it (and held down by a bunch of books). But I'm worried it could become a stresser for her, since it is in a room that we walk through. She's in the same corner as her old forty gallon tank but we still walk over to her cage and stuff. We were cleaning up the house in other places so we didn't have a chance to move out the 40 gallon tank, just set up her new bin, plus we don't really have a place to put the thing... but if we need to move it to keep her happy I'll of course do it. But she seemed pretty enthused by the mouse in her new cage so for now she's doing good!
Thank you to everyone who tried helping me out in this thread, and hopefully I won't be back anytime soon! (or be back with better news, anywho)