cant access my page

What did you do prior to the error…. were you editing code in functions.php in your theme?

Yes,

Turns out I had to delete and reload the theme, just to get back in

That works fine. Always back up any files you are working on….

You have to be real careful adding in php to a file, especially functions.php – it’s very easy to break.

For instance, you would rarely put any code starting with an opening php tag in functions.php

<?php

There is one at the top of the file, you don’t need another, just the actual code. I don’t know if you did that – but from the error message it’s a guess. It’s a common mistake folks make when they copy things from the web to put into that file.