Trying to Gain Weight - Loosing in Face

So, for two years now I've had hypoglycemia (what seems to be reactive), and for the past six months its been at its worst. I can't seem to eat enough. I try to eat as much as possible, but even if I eat a meal bar with maybe 5 grams of sugar in it, and 10 grams of protein, I feel good for maybe fifteen to thirty minutes, and then I'm "crashing". I'm really needing some advice. I don't know what to do, and I get at my worst when I'm walking around in stores. It's frustrating, at best.

Also, what's the connection with protein? I seem to feel better, even though only shortly, when I consume protein bars. How do I extend this feeling of stability? Is there a way to extend the processing of the protein?..

Lastly, over time, I've really lost weight in my face, and I'm trying so hard to gain weight. Any ideas?

Thanks