How Can Foot Injury Causing A Painful Lump Be Treated?

i dropped a very heavy piece of machinery on the top of my foot about a week ago. It did swell up and get bruised. I am still feeling pain to touch on the top of my foot and there is a lump. It also feels like something is moving when I feel the lump. Could this be serious or should I just let it heal. I can walk ok and move my toes.