You have no hope of success against Edward's army. Your victory at Stirling Bridge was a one off. Retreat and surrender to the stronger side. You could negotiate a peaceful solution.
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.