I used to have problems knowing when I was full up. I could eat humongous portions and never realize I'd had too much food. I also never used to feel hungry, even if I'd gone all day long without any food.
I'm very pleased to say that things have improved. Now I know when I've had enough because I no longer want anymore food. It may sound simple, but there's a point in the meal when the taste of the food is no longer pleasurable, that is the point when I've had enough and I stop eating.
I think everyone experiences fullness differently though, you have to really tune in and listen to your body.
Appetite is controlled by a hormone called "Leptin" when this is out of balance it can play havoc with your ability to eat the right amount of food. There's a lot you can do if your hormones are out of balance though, but the thing about hormones is that it's pointless trying to balance just 1 hormone in isolation. If Leptin is out of balance so are the others and correcting one hormone will not have much of an effect, since they all work together.
I know homeopathy is excellent and so are things such as Yoga and meditation, for hormone balancing, I think diet can also have a massive influence, although I understand, it is difficult to follow any "diet" when you have trouble knowing whether you're hungry or full. Stress also affects hormones massively, try to reduce stress in your life and things may just click into place on their own. I know it sounds stupidly simple, but I think stress is what causes most ill health these days and learning to reduce and deal with it better can work wonders.
I think if you try to be kind to your body and it'll be kind to you. But when it is playing up, I know it is hard to be kind to it and not get upset and stressed by its malfunctioning. Just try to go with the flow, don't push yourself too hard or fast and chill out a bit, that's what I've been doing and it has helped me massively!
I hope this helps you!
xxx