the tvos on my apple is 14.4(18K802)
Alright, that software is almost 2 years old, so a software update is in order.
let me guess, the model i have wont update any higher
Not at all. Your model is compatible with the current version tvOS 16.2.
I’m not sure why it would error on trying to update the regular way, but Apple Support staff will try to assist you with that, if you choose to contact them. They might ask you to bring it in to a Store or Service Provider.
There is an alternative method that you can try yourself: Restore and update externally through a computer, via USB cable. That will reset the device. Here are the instructions for that: Restore your Apple TV - Apple Support.