I would get it checked – but the GP is the place to go to -apart from anything else they might well be able to eliminate the possibility and they should be able to organise an x ray at out patients rather than A&E
Treatment is generally supportive i.e. pain killers, wool arch bandages etc, which I suppose you could offer yourself at home.
Basically, wouldn't warrant further investigation (XR etc) as management wouldn't change.
Metatarsal fractures readily unite (mend) by themselves hence little to be done for them.
After extensive googling I reckon I might have put a small stress fracture in a 2nd or 3rd metatarsal on my right foot. Is it worth bothering the nhs to get this checked (and in which case who, as it's not exactly life threating), or should I just be a man about it and wait for it to sort itself out?