I have been trying to run the IP updater for HOURS. I have changed my password several times, each time logging out of the control panel and then logging back in, to make sure it is correct as I am changing both passwords together. I know my username is correct as well. I'm about to lose my mind... Help please?

Check the location name. If you assigned your domain name a location name in the control panel, you need to use that location name in the IP update client as well.