My husband has the same experience as you in that he doesn't feel full no matter how much he eats. I, on the other hand, learned the full feeling quickly. Mine is more of a pain or lump in my chest when I've overeaten. I learned to slow down and stop at the 1/4 cup of food and see how that felt. I found that there really a feeling of being satiated or full. It sounds weird, I know. I still can't do much more than a 1/4 cup of food and I'm nearly 3 months post-op. I also have issues with certain meats. For example, I can do ground chicken ok, but chicken breasts, even shredded and cooked in a crock pot all day so its super moist, just does not sit. I can do almost 4 ounces of fish, which I'm loving, and it sits very well in my pouch.
The best advise I can give you is what others said before: 1) get a scale and weigh out all your food to 4 ounces, 2) use a much smaller plate than a regular dinner plate (I went to a thrift store and bought a bunch of saucers and fruit bowls), and 3) listen to your body after you've eaten. Hopefully, after some time, you'll eventually figure it out.
Good luck!