VL hopefully this will be the first day of the rest of your life!!
I started shred in January. I am 43 and just over 5 ft. I was a long term exercise resister. I was around 1.5-2 stone overweight. After many little 'pushes' and 'pointers' from life I decided I was going to get a grip and get & keep my body young before it got too old.
Since that first day I have exercised most days - maybe missed around 10 days in total. I like exercise some days. I always feel glad when I have finished. I feel fairly twitchy on the days I don't exercise. I have completed 30DS, 6W6P and am now on week 4 of the Couch to 5K that Bupa have.
This was all because I did that first 30DS day.
The differences I have seen in myself
a) body wise lost 1 stone, 3-4 inches from bust,waist and hips. I am now a healthy BMI. I look great!
b) life wise I am warmer. I have much more energy. I have more body confidence (DH enjoys this alot!
). I have much more gusto and joi de vivre. I am happier. I am sharing more things with DH (have been hill walking, he runs with me) and it has increased our 'togetherness'. I feel like an achiever. I have more general confidence in myself. Now I have met this challenge I know I can tackle whatever else inlife I would like to have a go of. 
So, back to the Shred. I did 10 days at each level with no days off (except for day 30 which I did on day 31). My diet was fairly 'clean' anyway so I didn't make big changes. I did reduce carbs though.
I saw results within 10 days using the tape measure.
The aching will disappear in a few days. It's your muscles growing and repairing. The pain is your friend.
Sorry for the long winded reply but I was a hopeless case and if I can do it, you certainly can.