Well what is happening to you sounds like classic neuropathy. First the numbness and tingling. This is a sign that your diabetes is affecting the nerves in your feet. Actually, they are probably affecting more than just the nerves in your feet but this is what you are noticing at this point. Now, when you get to the point where you get burning and constant pain in your feet, you have reached the point where the nerves are starting to die. When the nerves die, you get pain. Go to your Endocrinologist and also see a podiatrist and talk to them about what is happening to you.
There are several medications specifically on the market to deal with the pain from neuropathy AND there are several clinical trials going on nationwide for medications that can help halt the neuropathy and regenerate the nerves in your feet. BUT to access any of this you will need to see your doctors! Good luck