My advice: Don' t shoot. So far you only have a surprised, perhaps curious, most likely frightened bear, which will run away (which it did). You shoot, and you' re 5 feet away from a threatened, wounded bear. No way a bear is going to drop when you hit it, assuming you can hit it in that situation.

Surprised and curious, or threatened and wounded. You decide.

The only thing you might have done differently is to yell at the bear before it got that close. You were probably in more danger from your heart giving out than from the bear.