I noticed one day that the bottom edge of my thumbnail had a small hole in it. The edge of the hole was sticking up a bit and sharp, so I got a pair of nail clippers and proceeded to clip at it. The more I clipped, the more came off. The nail just wasn't connected to the nail bed. There was no pain whatsoever, it was almost like removing those cheap fake nails. Eventually, the whole nail came off. That has been about 6 months, and it still hasn't started to grow back. I can't recall hurting it in any way prior to this happening. The nail bed is just ridged and lumpy with a large lump in the middle of the nail. It feels almost like velcro, odd as that sounds. Will my nail ever grow back? None of my other nails have had the slightest problem. It's very ugly, so I usually go around with a bandaid on it. Is there anything I can do?

You may have dome something to cause permanent damage to the matrix where the nail plate cells are born. If so, a new nail won't be able to grow. You could also have 'nail atrophy' where the nails will virtually fall off on their own because the matrix has atrophied. I would see your physician to rule out an internal disorder.