I'm sorry to hear about this. I don't think that given your condition that artificial protien powders are a good idea, it sounds like your body would thrive best on real protien and amino acids found in real animal products.
Most supplements these days are processed and are nothing in comparison to the nutrients found in real foods. You only know if you try, but I doubt any protien powder is going to help you much. You probably need the best possible diet (real food) for your needs.
I have no idea what your financial situation is, but if I couldn't work to make more money and my parent's couldn't support me, I would make a Go Fund Me page.
Honestly, I've seen people donate money to personal causes that are much less important than yours. I am certain if you explained it exactly like this, people would donate money to you so that you could afford enough meat to live on and be healthy.
Also, I would take my kayak out and go fishing and collecting oysters and other shellfish. Some really good meals for absolutely free around here! I saved my money up for a folding kayak so that I could ride to the ocean with it (I don't drive).
I would also get my hunting licence and go hunting to collect some meat, the only reason I don't do that now is because I dont like killing animals but if I had to in order to survive, I would.
Sometimes local butcher shops will let you buy meat in bulk, which ultimately costs less. You just need to have a big freezer to store it in.
Or if push comes to shove, you can always go hunt some wild game and store it in the freezer, it'd last for a long time.
Also, I'm not sure what your condition is called exactly but are you sure that it's actually a protien deficiency, and not a carb deficiency? I'm sure you've been diagnosed properly and everything, I hope.
Because what is worrying to me is that low carb and high protien diets also cause the same symptoms you are having. Too much protien and not enough carbs will force the body to eat your muscles and take protien as a fuel because you aren't giving your body enough carbs, and forcing your body to use protien as a fuel is toxic and creates ketones, that will ultimately cause kidney and liver damage and eventually death.
I hope your condition is being looked after by a doctor because your symptoms don't seem rare to me, they seem quite common with what happens when you starve yourself of carbs and eat too much protien.
But I'm sure you are intelligent enough to not self diagnose yourself, so if your doctor diangosed you with a protien deficiency problem, I guess that's what it is.
If you're under a doctor's care and have a specialist and have a specific disease condition, the experts on this would be nutritionists. I say this because you don't mention the name of your disorder or what the doctors recommend, and without knowing what's going on, we can't know what you're able to digest. Perhaps if you tell us more about what exactly is going on it would help. Meat is the hardest food to digest, so it doesn't sound like you can't digest food, something else is going on, but we don't know what. As to the above, protein powders don't use "artificial" protein -- protein is protein, no matter the source. Some sources have more complete proteins than others, and some are more digestible than others, but protein is protein and protein is always made up of real amino acids -- that's what protein is. But supplements aren't cheaper than food. If you truly can't afford to buy basic food, it's time to look into government assistance. The only really inexpensive protein sources are beans. By the way, meat isn't better protein because it's acidic -- the acid to digest protein comes from a properly functioning digestive system, which produces the acidic environment when protein is introduced. Any bean combined with a whole grain will give you a pretty complete protein, but animal protein is always complete. Nuts and seeds are a great protein source, but hardly less expensive than inexpensive cuts of meat.