Help/Opinions Needed, Exercise Regime using 30 DS/BFBM

apologies for the immense essay I have written, I just want to give people a clear picture of me and what I want to acheive.

I want to start an exercise regime, my main goals being to lose a couple of dress sizes and tone up. The problem I have is that I can never get the balance right. I start off too easy, then get overenthusiastic, pile on more and then have to take a couple of days break to recover and in that break I quit.
I am someone who used to be quite active and fit but not so much now. I work 12.5 hr shift work at a hospital so am used to running around, opting for stairs instead of the lift. Im 5'2", 130lbs and am an annoying pear shape, top half is 10/12 (although my shoulder/chest area is more of a size 8) and bottom half is 12/14. I used to be 98lbs at my skinniest, my happiest most confident weight was probably 107lbs, mainly because all my clothes fit me perfectly at size 6/8, no tight areas around the thighs or baggy droopy bits at my chest, lol. But I dont want to focus on weight, as I know muscle mass is more than fat etc. My dress size goal is 8/10.
A while ago I started 30 day shred, after 1hour of zumba Wii ( i used it as my warm up). After 3 days I felt nothing (im some one who likes to sweat and feel the burn) so I added banish fat and boost metabolism. I gues what I should have done was replace 30DS instead because I ended up in soo much pain, took a break and never went back.
Starting fresh again, my idea of the perfect plan for me was to eliminate zumba, Do BFBM on my free days, and only 30 DS on my work days. Build up slowly that way until Im confident enough to stick with a demanding regime of Insanity... Any thoughts? Would really appreciate any feedback!
P.S. I know about the importance of nutrition and healthy eating so no help needed in that department.