Weird thing on face

My facial Acne has significantly cleared up in the last 2 or so months of my new diet etc. However I have this one thing on my face that will not go away. It's a little below the corner of my mouth(not a cold sore) and it was a zit at some point but now it's a neverending scab. I've literally had it for a month and a half now. If I leave it alone it forms a very painful scab that is very very dry, if I keep removing the layers of skin it gets a little better and is not painful. I've tried tea tree oil and evening primrose oil but no avail. I wish I knew what it was because it's driving me crazy. Thanks for any help.