The testing team somehow broke my entire codebase. On the release branch.

but has it been released ? that is the question

Did they actually 'break' it, or discover it was 'broken' (in the sense of having some bugs) to begin with? I mean no offense, i am simply unfamiliar with the terminology. Seeing as in QA role, I am not allowed to touch the code of another coder during tests.

You have a testing team.... We have to do everything including release and support...