could have been the trauma to your foot that caused adrenaline and/or immune system to kick in which made you feel better, I just recently had a period of several days improvement after fainting, albiet i had to go into hospital for fluid replacement, it was kind of awkward explaining how severe my ME can be, being dehydrated and low in phosphorus but at the same time feeling more energetic than usual! I have had other periods of improvement when i catch a cold - its like it jolts one of our many systems that aren't working properly into working a bit better - maybe temporarily, maybe, hopefully, permanently!