My thumbnail is peeling and has a v-shaped furrow from top to bottom. Can anyone help?

My left thumbnail has been very lumpy for about 20 years. The lumps aren't "ridges" and can't be described as horizontal or vertical. They are irregularly-shaped, raised areas - as if the nail were mimicking rolling hills. Fine vertical ridges cover the whole nail and a deep, v-shaped furrow runs through center length of the nail. The lumps are not in the nail bed, but move upward from the bottom as the nail grows. Occasionally, thin, rust-colored, vertical stripes also appear and grow out with the nail.