Frustration and improvement

So, I have this DVD of Leslie Sansone's that is a 5 miles walk.  Back in September before things went south, it had become what I would use if I wanted to do an easy workout.  Completing the entire thing was easy for me and yet still burned a decent amount of calories (typically around 500 for slightly over an hour).  I was giving more than she asked for.  When I do this DVD I always do the arms moves even when she isn't, I always "sit down low" even when she doesn't, and I spend most of the time somewhat "boosted".  So, Monday I decided to get back to working out.  There's snow outside and there are Christmas yard decorations draped all over the room where the treadmill is so that they can dry before being put back into their boxes.  So, I was going to do my 5 mile walk with Leslie.  Or so I thought until I started doing it.  It wasn't easy anymore.  I made it all the way through the first 2 miles and slightly into the 3rd and that was it for me.  My main issue was that my feet were killing me, but I was also very tired.  Ridiculous!  I was so mad and frustrated with myself.  I wanted to cry.  Even worse, I wasn't home alone when this happened to me.  My husband and one of our friends were here.  Lovely!  A few months without exercise had turned me into a failure, as if the regain of over 20 pounds wasn't bad enough.

So, I licked my wounds and put the DVD back in yesterday.  It WAS NOT easy, but I did all 5 miles.  I also did it at the higher level I used to do it at.  I burned 639 calories in 67 minutes.  I still want back to where it was a light, easy workout, but this is improvement and I'll get there.  Then back to the treadmill and running again.