When you’re a cop and you’re afraid, you can’t call 911. You ARE 911. If you can’t act like it, then it’s time to find a new job or a position on your department that keeps you away from danger.
There’s no shame in not being able to do a job that only a few people are really equipped to do. If you don’t think you can handle being a cop, then don’t be one. But if you know this and someone gets hurt because you didn’t get out when you should have, then that’s on you.