Gravity

Sadly gravity is not the only thing preventing you from swinging around heavy objects. If you tried to push a car in space, you'd only really end up propelling yourself away from the car.

You'd be applying an equal force to yourself and car. Since the car has a much larger mass, youd be the one mainly pushed away.

Thus, you need to first increase your own mass by devouring everything. Start with smaller objects and gradually increase the size.