It shouldn't surprise me but it's kind of shocking what bad attitudes most of you have in regards to your ability to effect change. You can do anything you want. It seems Americans are not only affected by the urge to binge and eat poorly (I guess as comfort for their unsatisfying lives) but have also internalised the idea that it's far too hard to change, be healthy and get fit.
I mean, pretending that your life is over without any possibility of change in your late 30's is ridiculous. You have to accept who you are in terms of body type, your ability to gain or loss weight, etc., but you can absolutely become your best self, the absolute best you can be.
The biggest challenge, aside from all this negative naysaying, is this idea that the only weight loss pursuing is rapid weight loss. That's probably the worst plan to pursue in any circumstance. Why does it have to be so fast? What's the hurry? The way to effect long-lasting change in your life is lay the groundwork, lose weight properly, really change your habits and body composition, as you claim you wish to do. I can't understand why, if that is what you want to accomplish, you're sitting on the fence wondering whether it's a worthwhile pursuit. It's your life, your health, your body. Why wouldn't you want to do it? Every day you exercise and eat right you're better off than you were the day before and that's the only progress that should concern you.
Taking two weeks off work to get started? These changes would be for life, mate. You think you're going to make sufficient progress in two weeks? Get over yourself and realise that isolating this goal is...I don't even understand what you're on about. This is your life, these efforts and activities should be integrated into your daily life. Sounds like you're just trying to make it harder than it ever would be so you can keep talking yourself out of it.
There are several components required here for success: exercise, nutrition that supports your training and your goals, supplemental nutrition (not fat burners and other nonsense), sorting out your digestion which is probably fucked, recovery and getting enough sleep and guidance in the form of a trainer. Don't even focus on the results - focus on doing the work.
Yes, you can change your body but more importantly you can change your health, both physical and mental, and realise that you're capable of so much more than you think. You can build confidence, how you present yourself and how you interact with the world. And yes, all of that will change what you're capable of and what you perceive your future to be. Good luck.