It could easily just be very bruised, specially if you can move it, but Its possible that you have broken or fractured something. I managed to break two toes kicking a busines class seat on a flight back from Dubai.
Very painful.
Regardless of whether it is broken, there is pretty much nothing that can be done, and treatment is basically same, so dont waste your time with A&E or the GP.
Apply cold packs to get the swelling down. Take ibruprofen for inflammation, and paracetamol for the pain. For the first day or two, it will help to keep it elevated, and rested..
Counter intuitively, after the first few days, you should make sure you walk on it, and dont try and imobilize it, as it will affect the healing. Also, dont be tempted to wear flip flops or open shoes. Wear the most enclosed shoes that you can actually get on your foot. I ended up wearing my OH's DM's which were a size bigger.