me - Zion speaks. Her groans are what bring down retribution in kind on Babylon (Jer 50:17; Psa 102:13, Psa 102:17, Psa 102:20).
empty vessel - He has drained me out.
dragon - The serpent often “swallows” its prey whole; or a sea monster [Grotius].
filled his belly ... cast me out - like a beast, which, having “filled” himself to satiety, “casts out” the rest [Calvin]. After filling all his storehouses with my goods, he has cast me out of this land [Grotius].