How do I fix my stupid toilet?

Buy a whole unit, including the flapper. It’s very easy to install, and installing it all at once is generally a good idea because once they start to break, other stuff will go wrong, too. Get one at Walmart. The instructions are very complete and you will feel quite victorious.

I actually didn’t see a whole unit at Home Depot. /sigh.

Do the instructions include how to keep the toilet from filling back up?

Yes, but you answered that correctly yourself. It’s a valve at the end of the water supply pipe, shut it down, flush, and then if you want to you can bail out the last bit of water, although I usually just let it stay.

thanks.

still feels dumb lol

You’ll see. It is a very satisfactory feeling to tackle something new and do it right. Men conspire to keep you feeling that way so that they can pretend they are necessary.

You can do this! There are different types of flappers and flushers.
Find out what kind you have and then get that kind to fix it. Yes, the shutoff valve for the water is there by the floor. I’m sure that there are some good online sites that can give you very detailed instructions, with diagrams to help you. Good luck!

flappers and flushers….no wonder I call my plumber….He’s a family friend and only charges $20 for minor stuff.