How do I repair a leaky toilet?

where is it leaking? if from underneath, the seal needs to be replaced --- a plumber's job; if it's from the tank, again a plumber's job,,, but this time of year .... and depending on where you live, the tank COULD be 'sweating' from the warmer water/colder air in your home .... take a paper towel and wipe the sides and BACK of the tank if you can reach it and if it's damp , the tank is sweating .... will stop when the humidity/temp are better balanced.

There are tutorials on DIY toilet ring replacement, but personally it's not a job I would tackle ... entails removing the bolts to the side of the bowl -- and they may well be rusted .... and the job goes down the drain from there !

get a handy man or plumber, from the sounds of it you'll mess it up even more

I had a leaky toilet for a few months, didn’t do anything about it then my quarterly water bill came and it was sky high! Get a plumber or handyman to fix it ASAP.

Yes, most definitely call a plumber. Soundsto me like a leak somewhere in the seal. Good luck!

hire someone a professional. I assisted with putting in a toilet forget it too much trouble in my opinion.