Answer

Hypoglycemia would make your dog seem low energy, weak and tired. Extreme cases would cause seizures. Therefore, no this would not be hypoglycemia.
The foaming at the mouth and vomitting usually means your dog ate something bad, sometimes even toxic. I'm very happy to hear your dog is eating and feeling better. It's important to make sure your dog is eating to prevent hypoglycemia.

Your dog's progression means whatever he ate is passing, so give him some more time to recover. To help him, I would suggest giving him warmed soft food which is eaier on the stomach. You can use the boiled chicken and rice or you can use his regular food (if hard) soaked with some warm broth or water. You can even use baby food (no chunks or noodles) that's been warmed and let him eat that. Give small amounts of food so you don't overwhelm him.

I hope this information was helpful to you and please let me know if you have any further questions, I'll be happy to help.

Best Wishes,
~Olivia