Swelling after removal of cast is expected in most of the cases.
Next Steps
You have to keep doing Ankle and foot exercises as much as possible. While sitting or lying down, keep that foot raised on a pillow or some support surface like stool or chair and make sure it is kept higher than the heart level.
Health Tips
You may try using a "Pressure Stocking" which will be available in Medical/Surgical shops or Physiotherapy clinics