My biggest fear when carrying a fire arm, and I've been extensively trained, is that someone would get the drop on me and take it away. That happens more often than people know. Taking good, safe, firearms training and LOTS of it, along with doing a lot of target practice needs to really be part of a weekly or monthly (at the least) routine. Taking a second to breathe in, aim, and fire on exhale will help with accuracy but adrenaline can really mess with you. The department I worked for had a policy that if you pulled your weapon and shot, and didn't hit your target, was an automatic 3 day remedial training course at the range. The more training and repetition you have, the more likely your are to actually hit something if you need to shoot.
Also, should be mandatory reading: http://www.paxtonquigley.com/
She' has authored several good books about being female and being armed, the liabilities and responsibilities of gun ownership.