Core Synergistics does ask for (though not outright require) weights or bands for some moves, including the move I find to be the move complete workout in all of P90X.
I gotta say- it sounds like even more than a workout regimen, you need a substantial change in diet if you want to get serious about fitness. More regular, nutritionally sound meals will do a huge part in getting your body into the shape you want it.
For example, eating "nothing" instead of a boiled potato is not a better alternative for any area of health, but there are better alternatives than either that taste great! Lots of salt on baked chips/fries is much worse than a little healthy oil, but snacking on nuts, veggies, or (unbuttered) popcorn are all way better than either of those choices- but all three (well, except veggies with no dressing or whatever) still require moderation.
Generally while getting into fitness you want to try and increase the amount of protein in your diet while reducing fat, carbs, sugar, and sodium. You want to reduce the amount of processed foods to an absolute minimum while upping the amount of freshly prepared or raw food. The obvious conclusion is that junk food is out, and you can save tons of calories by not drinking them alongside meals anymore (soda is really just a terrible blight on any diet). Eating nutritious meals will do you much better for your fitness goals than just eating less, and in extreme cases like some you are implying (chips for dinner) you will actively be working against your body, because without taking in enough energy your body won't know what to do.
P90X comes with a very detailed nutrition guide. You don't have to follow it to a tee or make recipes from it every night to get results, but adhering to its general principles will do more for you than any particular workout ever could.
