30 Day Shred

This is for those of you who have done the 30DS religiously every single day.

I just have a few questions about it. I did it back in the end of Nov 2011 to the beginning of January 2012 and I lost a total of 13 lbs. I continued to do it although I had finished the 30 days. I hit a plateau in March and quit working out (big mistake!) I did try Banish Fat Boost metabolism and The Biggest Loser cardio max dvds, but the Banish Fat dvd was too much for my body to take. I didn't want to injure myself on that one and the Biggest Loser dvd didn't really do anything for me. If I did the full 60 minutes then yeah it worked a tiny bit, but for 60 minutes it didn't do much. Since then I haven't really got back to exercise and eating nutritiously (my fault of course)
I started the 30DS on Monday again, but it didn't do much for me I didn't sweat much and I didn't really feel the burn throughout my workout and the next day I definitely didn't feel sore or anything. I have thought of doing levels 1, 2, & 3 in a row to get the most out of my workout. Should I do this? I also can just drop the 30DS and start working on Banish Fat Boost Metabolism dvd, but I worry I won't be able to do the full 60 minutes of it (I think it's 60 min.) I also worry that I may injure myself too.

What do you recommend?
Feel free to give me any helpful tips.
Thanks for reading btw.