Suggest Treatment For Blisters On Feet When Suffering From Diabetes

I have just developed a friction blister on each of the bottoms of my feet heel area. I was on a vibration machine for 10 minutes barefooted. How should I treat the blisters to avoid diabetic sores. Recently lost 55 pounds and have always had my tennis shoes. when there today straight from work, wearing short heels, they said no problem just do it barefooted. how should i treat this blisters to avoid sores. Thanks in advance for your answers. I am diabetic. that is why I have worked so hard to loose the weight.