You are no quitter! You would rather die that surrender to Edward without a fight.
You've come this far. You have the dignity, hope and trust of all your men on your shoulders. Stay and fight this battle.
Your safety is of the utmost importance. Employ only a few of your men to fight. You know it would be fighting a losing battle, but you need to save face against Edward. You will make a few losses, but what are these in the bigger picture?
Play a card.