I am suddenly afraid of dogs. What can I do?

For about 5 years I worked with all kinds of dogs as a kennel attendant, and never EVER had any problems with fear of dogs or anything, I knew how to be the alpha. I haven't really been around dogs in about three years, and am suddenly very afraid of them. I feel like I can't read their body language anymore. I try to be confidant when approaching a dog, but fear usually wins out in my heart and I end up on the un-friendly end of a growling dog. What the heck happened to me?? My sister just got a puppy, and I have been going to her house and familiarizing myself with him, and I'm not afraid of him, but if I see a dog on the street, or if I enter the home of someone else who owns a dog, I get really scared. What can I do?