WOW - So glad to hear he's doing a bit better
Roxy had hypo episodes when she was little. The breeder used to feed her a little chicken with honey drizzled on top, then she would be some wet food.
As mentioned, Cesar's makes a canned food that lots of dogs go nuts for. It isn't the best food, but if it works for now, that's all that matters. You can smash up some dry food and 'sneak' that into the mixture too!
I also suggest getting a baby syringe, and force some pedalite, often and daily. This will need to go on a few more weeks, until he grows a bit more.
Keep us posted.