If you have mental problems when it happens such as depression or other problems, they can be magnified. Some police departments require mandatory review by mental health professionals after an officer involved shooting incident. Such review is not bad. Certain events can compound the problem like having to shoot someone you know or associated with. Also hostility from the other persons family, friends, and associates can create more complex issues.
Family support is vital.
Reinforcement that you are still the same person helps. It is probably the best medicine of all. You still must expect some hostility. Some will feel you did the wrong thing or had other options. The average person will get through it.