Messed Up Client Email Campaign, Facing CXO Escalation

I work at a MSME with 5 years of experience working as a SDE3

3 campaigns needed to be triggered to a national bank which is notorious for not giving cc limits even after decades of relationship

Users count was small

First campaign- 247 users

Second campaign- 446

Third campaign- 49

All the mailers were approved but then my confused ass fucked everything up and for 2nd and 3rd campaign the Subject of email was sent with a postfix test

Within a second I identified the issue but triggered the mail with correct subject but by then it was too late

Now our PM is threatening me that he will go to CXO levels and now i am anxiously waiting dor what will happen

And all this is happening when my review is due in april

TL;DR:

SDE3 at a small MSME here. Had to trigger 3 email campaigns to a strict national bank client (low user counts: 247, 446, 49). Everything was approved, but I accidentally sent campaigns 2 & 3 with a “test” postfix in the subject. Fixed it within seconds and re-sent correctly, but damage was already done. PM is now threatening escalation to CXOs, and I’m sitting here stressed waiting for fallout while waiting for mu appraisal that is due this april.