Juice is great! My favorite combination currently is kale, cucumber, celery, parsley, lots of ginger, lots of lemon.
I eat veggie sticks with guacamole fairly often. With all the fiber and fat, it’s pretty filling. You could probably also keep a few hard-boiled eggs around for when you just really need to eat something ASAP (besides a celery stick :p ).
Stick with it, it gets better (eventually)!