What does it mean when someone tells you ....

If you have to 'Bite the bullet' it means you have to face or confront the very thing or person you've been avoiding.
Since that's the only way to move forward

Take the pain and do it.

When the time comes, bite the bullet and take the punishment without a fuss.

It's a phrase used historically, from the practice of having a patient clench a bullet in his or her teeth as a way to cope with the extreme pain of a surgical procedure without anesthetic, though evidence for biting a bullet rather than a leather strap during surgery

Suck it up, deal with it, quit whining, take it like a man, umm they're all quotes implying whatever the situation do it anyway...

Get right to the point, nothing held back.

Do something unpalatable

Own up..

Get new sets of teeth because that bullet just ruined them?

accept responsibility/liability/consequences

Do something stupid

It depends on what circumstances youre in...