I know it's easier said than done Anje, and forgive me if I'm teaching you to suck eggs here, but my advice would be to take a mental pause to ask yourself why you're eating before you eat anything. If it's genuine hunger, carry on. If it's because you're stressed, bored, or any other emotional reason, then do something else that would help you address it more effectively. If it's, say, because you're feeling stressed, do something else that helps to de-stress and relax you, but not replace it with another vice, such as drinking.
Any alternative behaviours don't have to necessarily be healthy, as long as they're not unhealthy. Remind yourself that eating doesn't actually address the stress you're feeling, it just diverts you from it for a bit. Chances are, once you've finished the food/snack, the stress is still there and you crave more. If you think beforehand every time you eat emotionally, then respond in a healthier way, after a while the new behaviours become more habitual.
After Christmas though, of course.