It wasn't necessarily a bad decision to take antibiotics but many people do have to actively rebuild healthy gut flora afterward,

In general, eat/drink some probiotic foods such as yogurt, sauerkraut, kombucha, kefir (dairy or water) to encourage a healthier gut community.

Also eat prebiotic foods that will feed the "good guys" in your gut. Examples of prebiotic foods are garlic, kale, mustard greens.

You mean you took antibiotics back in August and you think the oral thrush is related to it now in December? Seems extremely unlikely that such a large time window would cause an oral candidiasis infection. Presumably you would have recovered your mouth/esophageal/gut flora since then, seeing as it is very unsterile in there.

To recover from any antibiotics it is helpful to eat the probiotic/prebiotic foods @Nance mentioned.

It should also be important that while you regret having taken antibiotics, in the future it is important to identify that antibiotics play an important role in dealing with infections and are lifesaving. Yes, they are heavily abused and create resistant strains, but we can go right ahead and blame factory farming for that one. If they work on you and you have an infection that could be dangerous, use them. I had a friend who wouldn't treat a simple UTI with antibiotics, and she ended up with a raging infection that has greatly reduced her fertility, they are not sure to what extent yet. Also it helps that I did two years of microbiology/immunology and learned about how easily bugs kill you, that will make you respect antibiotics for sure.

Hopefully your thrush clears up, that doesn't sound like a good time! Enjoy the kefir in the meantime!

Antibiotics mess you up, get as many opinions as quickly as possible before deciding if they are necessary. Point being they destroy your gut flora, which never fully recovers, although your body in time will become accustom to the new balance of bacteria, it will never be as it once was. And probiotics will help but only in small amounts, as you have hundreds of strains of bacteria that are beneficial and only a few.can be cultured. Also if you over populate will the same type of probiotics you are further impairing your body's ability to regenerate its own. For this reason after antibiotics I would recommend going full out with probiotics, as many brands, cultures and diversifies as possible. Grab several supplements, yogurts and purchase some water or cocnut Kefir grains before finishing your antibiotic course so that as soon as your done you can introduced massive amounts of as many strains as possible. Don't be cheap, get good ones, with an active delivery system to ensure they get to the gut, and double up on recommended dosage. Take some on empty stomach, as these have a higher chance of reaching the intestines, and some with food to help digest what you eat as you no longer have the same digestion as you did before, and digestion takes up an incredible amount of effort on your body's part, help it out for awhile. Also some probiotics might infuse itself into the food you eat helping it get to where it needs to go, but most likely in small amounts. And do not continue probiotics for too long, I'd recommend a month tops of heavy injection for the main point of not allowing space for bad bacteria to proliferate and not so much as to replenish your good bacteria, your body and healthy diet will do that better than any probiotics ever could, let it do so.

Also the multiple opinion might lead to different antibiotic prescriptions (which in Canada getting a doctor visit and a prescription is free) last time I had strep throat I went to three different doctors (my family GP and 2 walk in clinics) got a prescription for clarithromycin, clindamycin, and amoxicillian. Took all three prescriptions home and researched which was less harmful to gut flora and decided to go with amoxicillin as the other two showed to be harder on your system. All were the same length in terms of a 10 days course with amoxicillian being in the highest dose, however thisnis what I decided on, and I'm glad I had the choice. Also if you think you need antibiotics, or even if there is a chance go get your opinions from as many docs as you can ASAP, as the sooner you catch it, the lesser the dose antibiotics your going to need... Obviously. Then proceed as recommended in the above post. I am not a doctor, just someone who spends ALOT of time on the Internet reading as much medical literature as possible.

Antibiotics mess you up, get as many opinions as quickly as possible before deciding if they are necessary. Point being they destroy your gut flora, which never fully recovers, although your body in time will become accustom to the new balance of bacteria, it will never be as it once was. And probiotics will help but only in small amounts, as you have hundreds of strains of bacteria that are beneficial and only a few.can be cultured. Also if you over populate will the same type of probiotics you are further impairing your body's ability to regenerate its own. For this reason after antibiotics I would recommend going full out with probiotics, as many brands, cultures and diversifies as possible. Grab several supplements, yogurts and purchase some water or cocnut Kefir grains before finishing your antibiotic course so that as soon as your done you can introduced massive amounts of as many strains as possible. Don't be cheap, get good ones, with an active delivery system to ensure they get to the gut, and double up on recommended dosage. Take some on empty stomach, as these have a higher chance of reaching the intestines, and some with food to help digest what you eat as you no longer have the same digestion as you did before, and digestion takes up an incredible amount of effort on your body's part, help it out for awhile. Also some probiotics might infuse itself into the food you eat helping it get to where it needs to go, but most likely in small amounts. And do not continue probiotics for too long, I'd recommend a month tops of heavy injection for the main point of not allowing space for bad bacteria to proliferate and not so much as to replenish your good bacteria, your body and healthy diet will do that better than any probiotics ever could, let it do so.

I don't mean to sound harsh, but have you been diagnosed with thrush by a reputable doc? Or self-diagnosed?