Didn't go through all the replies but I'll just say a few things that are always worth repeating.
Very sorry to hear this, and I can't believe no doctor has been able to give you some good advice so far. And I don't mean I don't believe you, but rather that I find incredible that healthcare can be so bad in a Western country which I assume you live in.
Most certainly not unique at all.
Exactly the same happens to me and everyone else I know. "Starving mode" is definitely a thing in the human body, one of the most important survival strategies we've used in the millennia (but unfortunately more harmful than useful nowadays).
In general, as I've already had a chance to point out in these forums, the best strategies to lose weight effectively and permanently are:
- keep the glycemic index as low as possible,
- avoid calorie-dense foods,
- exercise everyday (mostly aerobic exercise such as running and swimming).
An optimal diet consists of whole grains, legumes, nuts, seeds, occasional animal products (preferably fish), and a wide variety of fresh whole seasonal fruits and vegetables. It's important to choose fresh whole foods and not eat animal foods everyday. Such a diet will have the following beneficial effects on your body and health:
1. The association of whole grains and legumes provides a complete aminoacidic profile and lets you avoid animal foods which are much more calorie-dense and promote obesity (you may want to Google the E.P.I.C. study for more information about how a high protein intake is associated to obesity).
2. Eating fresh whole foods will ensure the glycemic index stays below a certain threshold, therefore avoiding further development of insulin resistance. Most industrial refining processes cause foods to increase their glycemic index. Soylent is probably the only industrial food I've ever heard of with a known and controlled glycemic index. Otherwise just eat fresh whole foods.
3. Avoiding animal foods and eating mostly plant foods will cause your diet to be far less calorie-dense, so you will no longer have to restrict the amount of food and put your body into starvation mode because you'll be able to eat higher volumes of food and still keep the calorie count low enough to avoid the excess.
4. "Fruits and veggies are good for you" because they're full of antioxidants, other than being the best natural source of vitamins and minerals. This will give you much more energy to do physical activity and will help you recover much faster after doing it.
Addressing your points specifically:
Not sure what picky means here, but it's probably a matter of habit. Many people I know or have heard of, no longer find junk food or animal foods so attractive when they switch to eating fresh whole plant foods regularly.
Maybe to achieve something you've never achieved you need to do something you've never done.
Cooking is part of our nature as Homo Sapiens, we've been cooking since the discovery of fire. It's our natural way to preprocess food in a way that makes it easier to digest when it enters our bowels. This is thought to have greatly favored the development of our brains, as our bodies could give it more energy because it needed less to digest food.
In today's world you can get someone else to cook for you, but if it's a business rather than a friend or relative they'll need to do that on a large scale, so they'll need industrial refinement processes to increase shelf-life and taste and the result will be utter shit. Stay away from that.
That said, I'd like to point out that there are probably a few lesser known recipes that can be both very healthy and very quick to make. Porridge takes literally 5 minutes in a microwave oven, so if the oats are good that satisfied both conditions.
Good news: fresh whole plant foods are generally much cheaper than animal foods and usually cheaper than industrial crap food. That'll help.
This is very sad: I think this alone explains at least part of your problems. I don't know what you do for a living, but if you could find a way to get that down to 40 hours a week I believe everything would be a little easier.
I believe the diet I described would greatly help you to change this.
Incidentally, the directions I've given above make this trivial to achieve.
Nobody can answer this, but the answer could likely be "no". This is indeed the ultimate goal of Soylent, but the way it is trying to achieve this is by implementing state-of-the-art science, which unfortunately is thought to be highly insufficient in some areas today. One proof of that is the lack of phytonutrients in Soylent (not because they are known to be unnecessary, but because it is unknown whether they are necessary or not).
From my personal experience, the best thing in the world you can do to your muscles is to keep the glycemic index low: the constant and prolonged flow of energy after doing physical activity will greatly help recovery and growth. This is only anecdotal, though. I go to the gym more or less regularly in the afternoon and I often eat chickpeas (together with other stuff) in my dinners because I know they have an incredibly low glycemic index together with all the proteins a legume can provide. I could tell how effective I've found this to be, but it would be too anecdotal / bro science.
Hope this helps.