Pop a 911

To take depression medication

I have to go pop a 911

Pop a 911

Call help.

In the song, she is talking about some mental health issue, so it basically means she wants to stop what she feels sometimes.

"My biggest enemy is me, pop a 911" - Lady Gaga 911

pop a 911

take antipsychotic medication

My biggest enemy is me
Pop a 911 -Lady Gaga

pop a 911

to hit a cop; to pop a cop

“hey did you hear what lady gaga said? pop a 911!”

“yep we letting pigs fly this year!”