I have the same problem with the control and inability to be moderate. Once something's open and I've had one I can't stop.
I don't know if it's better or not but I just give in until I've had my fill. I do this only occasionally and it doesn't seem to hurt. I've even wondered if it's a craving fat thing because I often feel better afterwards and don't crash. Often I'll eat 800-1000 calories this way.
The key for me is to hide this kind of 'food' away in a place I don't go very much during the day or is difficult to get to like a high shelf I have to get a step for. I literally have a drawerful of chocolate in my bedroom but as long as I don't open the packet, I'm OK until a craving comes along. I am PB 90-95% of the time so I figure these occasional binges comprise the other 10-15% of my 20%. I also usually eat only between noon and 6pm.