I cannot comment on the correlation of your early childhood experiences and your current craving for milk, but I'd think that, if milk agrees with you, it might not be something to freak out about, unless you are taking in many more calories than you need. I don't understand the lettuce-for-milk substitution. The bottom line is: it's just food, there is nothing to freak out about, you do not need to be perfect at eating.
I do not drink milk, nor do I eat lettuce. Culturally, milk has never been included in my cuisine. If I wanted to eat less of a certain food, I would choose another RPD-type food - for carbs, I eat fruits and organ meats. For fats, you can find RVAF sources other than milk, too.