From the Harvard Injury Control Research Center:

1-3. Guns are not used millions of times each year in self-defense

4. Most purported self-defense gun uses are gun uses in escalating arguments, and are both socially undesirable and illegal

5. Firearms are used far more often to intimidate than in self-defense

6. Guns in the home are used more often to intimidate intimates than to thwart crime

7. Adolescents are far more likely to be threatened with a gun than to use one in self-defense

8. Criminals who are shot are typically the victims of crime

9-10. Few criminals are shot by decent law-abiding citizens

11. Self-defense gun use is rare and not more effective at preventing injury than other protective actions

And finally:

This article helps provide accurate information concerning self-defense gun use. It shows that many of the claims about the benefits of gun ownership are largely myths.

https://www.hsph.harvard.edu/hicrc/firearms-research/gun-threats-and-self-defense-gun-use-2/