HUNGRY. Can't seem to ever get full

Honey💛
Help! Have any other ladies experienced this problem before? I am hungry all the time! I never seem to get full even after eating large meals and many snacks. When I do get full, it's usually for short amounts of time and I will soon have an appetite again. I think about food throughout the day and whenever there is food around I WILL grab some to munch on. It's recently come to the point where I'll go to another room to sneak eat and will scarf large amounts of my favorite foods so my boyfriend/friends/family won't eat it. I overindulge constantly and when normal people eat 1-2 of something, I'll eat 3-5 of something. I will feel full sometimes but I'll push my limits if it's something delicious. I ALWAYS have room for snacks and dessert when other people get full off a meal. I'm not taking vitamins of any kind. I'm average-slim and tall in build. The last month I've gained some weight since my awful eating habits (maybe only 5-9lbs)I don't want to gain weight so I exercise when I can.  
I don't know what to do to slow down my appetite without going on s strict or hard-to-stick-to diet  😩