.
Well, just judging based on the short history of what she's been given over "the last couple of months" and her reactions, it seems to me that the obvious diagnosis would seem to be that she simply no longer has the intestinal bacteria needed to properly digest what she eats. If she had had
diarrhea prior to the first antibiotic, then, perhaps there might (should) have been a question about some nasty
bacteria at play in her gut (I'm not talking
parasites here). Often enough we need to go past the basic 'first level' testing of stool.
So, now you have a specific probiotic plus the S boulardii ("Saccharomyces boulardii") to try...with the obvious 'disclaimer' that you (at least) get your Vet's opinion as well. And, remember to add in some pumpkin because (and, this is a lesson from that website) not only do you have to feed your cat, you also need to feed your cat's gut bacteria. (while Fortiflora often just doesn't 'cut it' as a probiotic, it can be useful with
some cats as an appetite stimulant because of its taste...so, don't throw it away)
Here's a reputable reference for Tylosin:
VeterinaryPartner.com - Tylosin. A careful read of that will probably ease any fear of using it with her should it be suggested down the road. You should know, though, that it's horrid-tasting and that knowledgeable folks will have it put into tiny gelcaps.
So, keep us posted............and, of course,
we would never refuse any quantity of pictures 
.