Sticking to my meal plan?

Ok so I have had anorexia since I was 13.. I am now 21.. I have been on a constant meal plan and maintained my weight for the past 6 months.. 3 meals and a snack. The problem is that at night when its time for my snack im still REALLY full from dinner and I have to force it down which just makes me miserable. Will it really affect my weight if I dont eat my snack on the nights im really full? my snack is small it is a dairy a fruit and a starch.. please help! thanks