There are two questions to ask yourself to see if you are being reasonable, or if you are being off balance.
The first is: Is my fear realistic? If you live in a neighborhood where there are break-ins, then the answer is yes. And appropriate precautions - a light on, and a different one at different times; or, in a bad neighborhood, bars on the windows; or, in a more prosperous home, an alarms system - is appropriate.
The second is: Is my fear getting in the way of my life. If you can't rest and relax at home; or you can't sleep alone; or you can't focus and enjoy work or reading; or go out without worrying about a break-in, then your anxiety is getting the better of you. Learning to relax and heal your fear would be a very good idea.