Xbox 360 failing to connect to Xbox Live

For a while now, I've been experiencing an issue on my Xbox 360 where I am able to log in, but it immediately states "Disconnected from Xbox Live" and forces me to use my account locally. My network is fine and other Live accounts work. Attempting to select "Connect to Xbox Live" on the guide prompts me to enter my password. I have tried both my normal password and a new app password, and they both return "Sorry, there was a problem. Please try again later." with the error code 8015190A. This occurs on all Xbox 360 consoles I have previously signed in on. I have attempted to delete and re-download my profile, but doing so causes the progress bar to get stuck about a quarter in then gives the error "There is a problem with the credentials you're using to sign in" and a similar code. I have also attempted to clear the system cache, but this did not fix any problems either. I believe this is due to an error with my account verification methods, but I cannot disable them and thus I have no way to know for sure. If anyone has any ideas I'd appreciate it.

:)