Hi BETSI . . .

. . . so glad you found us.
Maybe you could get one of those little alarm watches and set it for three hour intervals or something similar. After a while it should become a habit and that would be a good thing.
Snacks need to be nourishing and also enjoyable. Try to include a few carbs in the form of vegetables or fruits and some protein that slows down the action of the carb and keeps your blood sugar level for a longer period of time.
Personally, I like a couple of LF cheese stix together with an apple or a pear; or some cucumber or celery sticks with a couple of tablespoons of humus.