I'm so sorry about your cat, I will keep you guys in my thoughts & prayers!

A few questions:

1. Is your cat acting lethargic or tired, or otherwise sick? Third eyelid showing? Any drooling?

2. Any changes in litterbox habits?

3. What are you feeding him?

It sounds to me like 1 of 3 things.

Your cat is gorging himself/eating too fast, then vomiting up the food. If this is the case, the vomit will look like basically wet cat food, totally undigested, and will happen not long after he's at the food bowl. Our cats do this on occasion. Nothing really "wrong" and they'll eventually stop doing it.

Hairball. I think this sounds like the most likely culprit, given what you've described. Has your cat ever had hairball issues before? You can purchase some hairball remedies at the pet store, but also just try adding a little bit of olive oil or organic coconut oil (less than a teaspoon per day) to some wet food. Canned pumpkin (NOT pumpkin pie filling - just straight pumpkin) also works wonders on hairballs. These should lubricate things up to get the hairball to pass, even if it's a larger one he's having trouble with. If it's a hairball you might also see him gagging/dry heaving occasionally.

Third reason is diet. Have you changed his food recently or added anything new? Is it possible he's getting into something else without your knowledge?

I would suggest trying a higher quality food if possible, if you're feeding something less expensive like Friskies or Meow Mix. Aldi has a good grain free cat food, also Costco has two cat foods that are high quality and under $20 for a huge bag. Cats are notorious for having sensitive, fickle stomachs, and some cats have issues with less expensive foods. You might also look into a "hairball remedy" food.