Bear with me here.
Have you ever seen a martial arts movie?
If you answered "yes" then can you picture in your head one of those jumping spinning hook kicks? You know the one where you'd be doing an aerial 360 and finally landing your foot on the bad guy's face. And if you can picture one in your head, can you jump up and do one?
If you wanted to learn how to do one would you on your own simply try over and over again?
Would you buy a martial arts book, read it and then try?
What you'd probably do is find a martial arts expert to teach, guide and help you. You'd join his or her school, you'd start with the basics of punching and kicking and over time, with considerable practice, you'd work yourself up to that jumping spinning kick.
Now on to weight management.
Everyone's got their own mind's eye view of what it would look like, yet unlike jumping spinning hook kicks people seem to have it in their heads that they ought to be able to just jump up and do it.
Sure everyone's got an idea about what weight management looks like and ultimately like a jumping, spinning, hook kick it can be mechanistically broken down into simple instructions, but that doesn't mean you can just jump up and do it and frankly were it that straight forward, I'd be in another line of work and everyone out there would be as skinny and fit as they wanted to be.
The good news is there are in fact lots of folks out there who can help you with modifying your energy input, output or both.
If you're having a tough time just jumping up and doing it maybe you should find yourself a healthy living dojo or sensei, join, and just as if it were a true martial art be patient and don't expect to be doing the jumping, spinning, hook kick anytime soon but do enjoy your journey getting there.