Annie-
I can see where your confidence in this particular car may be rattled.
Your confidence in this MODEL of car should not be.
Ford has a lot riding on this, and this is perhaps the SAFEST car in the Ford Fleet.
Your brakes probably DID NOT FAIL all together. Your power brakes only failed.
In your self admitted panic, you didn't notice, but if you were to push the brake pedal all the way down, your car would have stopped fine, even from 70
MPH.
There is always a physical, mechanical way to brake... even if all the electronics freak out which sounds like it did in your case.
Short of the car being physically damaged in a crash or something, you will always have physical braking ability, but this will require much more physical effort from your foot than you are used to.
Do not panic, and always remember you have a parking brake also that does not involve any electronics.
See if your dealer will get you another FEH in trade. I would stick with it. You will not regret it!
-John