You could of course have an x-ray of your foot to assure there are no fractures, as hematomas are almost always present with a fracture. An X-ray can help differentiate a fracture from a bruise or sprain, which requires less time to heal.
Essentially it sounds as if you have sustained a severe soft tissue injury from the impact of the kick, but you may have a fractured toe as you mention a hematoma. A broken toe may take four to six weeks to heal, depending on the location and extent of the injury. Toe fractures usually heal well with rest and protection of the injured joint.
It is not unusual for bruising to occur from the contusion. If you elevated the your foot soon after the injury, the blood leaves the foot and helps lessen swelling. Resting your foot after the injury, along with applying ice is helpful. Wrapping your foot in an ace bandage helps reduce hemorrhage and swelling.
As it has now been four weeks, the blood from the injury should begin to fade as it is absorbed in the healing process, unless infection develops. If the area becomes more reddened, swollen for you develop a temperature, seek consult with your doctor.
My suggestion would be to avoid activities that result in increased pain or swelling. If your are still experiencing pain, Advil or Aleve can be purchased over the counter.
Casting usually isn't needed for a broken toe. If you opt for an x-ray and it is determined that the break is badly displaced or the joint is affected, surgery may be needed.
If you have questions or concerns, please do not hesitate to ask.