So if I use up all my login attempts, and I have to wait the 15 minutes, will it stack if I keep trying to login when the first 15 minutes aren't up yet?

It won't let you try again during the 15 minutes

I know, and I waited 15 minutes to log in, but it still says i'm locked out, and I don't know if it's something wrong on my end or if the 15 minutes are stacking

maybe contact a admin to get in that account if you are locked out

Try clearing your cache & cookies or try to login in a different browser