I changed the password on my gmail account, and now stringify cant access it, how do I change the password that Stringify is attempting to use?
Simply re-connect Gmail to Stringify.
when I click on the gmail thing, it says that it needs to be re-connected, and when I click on re-connect, the little window just goes away, and it doesn't seem to do anything.
Try force quitting the app and retrying. Also try going through the process to re-add it as if it were new - Things -> New (or + button).
when I try re-adding it, it just says "Error, you already have this thing" force quitting and re starting the app yielded the same results as before.
would uninstalling and re-installing the app help?
Sorry about that, I just made a change that should allow you to have >1 in your library (which should also let you re-add the existing one without error).