How to make particles attract eachother

I’m trying to make a simulation where a bunch of asteroids attract each other and eventually form a planet. I tried making a particle system where the particle object is a cube with collision and force field physics but they don’t affect each other. How would I do this or do I have to approach it completely differently?

Here is the second screenshot since I can’t have 2 images in a single discussion for some reason

For particles that affect each other you need the Moleculars physics Addon.