WOw, I sure hope you can keep it steady until you get to the Endo! I know how scary this can be.
I second the idea of exercise. Even a 20-minute walk can help bring down sugars after meals.
And there are some cheaper low-carb foods to fill up on. The more protein and fat you eat, the less you'll want bread, pasta, potatoes, and grains. Try eggs, canned tuna and salmon, Polish or Italian sausages, inexpensive hamburger, cheese. Cook frozen veggies (often cheaper than fresh) with butter (not cheap, but a little goes a long way) to fill you up with fiber and fat.
One of our favorite cheap-o meals is hamburger browned with onion and cabbage. Yummy, cheap, and filling!
Another is salmon cakes, made from canned salmon and pan-fried.
And eggs, every which way, can't be beat for protein, satiety, and budget-friendliness.
One of the best threads around (not here, unfortunately) for this sort of thing is "
Cheapskate Low Carb". Check it out for some great ideas!