A few weeks ago, I got a very small cut on the tip of my finger from a buck knife. The cut was all the way to the bone. I guess I didn't treat it right because while the inner part of the cut is healed, there are several outer layers that aren't coming together and there are exposed nerves still. I've had triple antibiotic ointment and a bandaid on it consistently for a couple of weeks and it still won't heal. What can I do to get the skin to come back together?