I started looking into this surgery because I was pre-diabetic and starving all the time. Like I just finished a huge meal, and my stomach hurt, but I still wanted to eat and eat and eat. My hunger has been increasing and getting worse over the past 10 years, along with gradual increases in my fasting blood sugar and other symptoms of metabolic syndrome like skin tags. My dad has diabetes (and got it when he was about 5 years older than I am now), so I knew what was coming.
The thing that really excited me about the surgery was that it provides a mechanism to reset your metabolism, to actually CHANGE your hormonal balance and your set point so that you naturally feel satisfied at a lower weight, and eating less food with less hunger. Now I am 2.5 months out, and I really feel it working - with the smaller stomach, it gets full faster, so ghrelin (a hormone that your stomach makes when it is empty that makes you feel hungry) starts to DECREASE quickly after you take your first few bites. Studies show that ghrelin levels are about 50% lower after bariatric surgery than before. And that has an effect - you really, seriously, truly feel much less hungry, even though you are eating way less.
In contrast, normally when you go on a diet, your ghrelin levels INCREASE compared to when you started. Studies show that after a 3-6 month diet without surgery, your ghrelin levels will increase by 50%. And that has an effect - you are much more hungry and so you want to eat even more and gain the weight back - it may even make you feel like an addict!
Since before my surgery, I would often feel hungry even when my stomach felt full, I can totally see why you'd be scared that you'd still feel really hungry even when your new small stomach is full. And I can tell you from experience - being hungry with a full stomach feels miserable! I can see why you'd be scared of that!
But I really want to assure you - the surgery works as advertised. You will feel satisfied, even when you are eating way less food than before. For me, the change in my hunger is like night and day - it's amazing!