So sorry to hear about this problem. To be honest, this is one that needs to be seen sooner rather than later, and you may need to speak with your doctor
before your appointment to discuss your concerns. You may be able to discuss this over the phone to see if he or she feels the same. As a person with diabetes, and also as a person who is on his or her legs quite often, you are at risk for having significant problems getting adequate blood flow down to the wounded part of your leg. These minor scratches can thus become very serious because your body isn't able to fight the infection without enough blood cells being carried to the area. While it sounds like you were treated with an antibiotic early on, it does sound that your problem might not be all the way resolved, and there may be additional therapy that is needed. While there are many excellent options available for people in your situation, most of these require the assistance of a medical doctor to guide the therapy and make sure that you return to your optimal health in the appropriate fashion. Please speak with your doctor soon.