Well, there have been many people who took the expression "to fall on one's sword" rather literally. However, I would urge you NOT to do this. I know people who have been stabbed, and it is extremely painful. It's also not that effective, and you would need to hit either an artery or a major organ. In the case of the latter, the pain would be exquisite, and death would take some time.
Once again, do not do this.