Actually, what you describe is completely normal human phenomena. Scientists think it is your brain’s response to cognitive dissonance and self preservation. Here are a couple internet articles I found, while looking really quick...
http://www.healthguidance.org/entry/17124/1/Why-Do-You-Get-the-Urge-to-Jump-to-Your-Death.html
http://nautil.us/issue/46/balance/why-you-feel-the-urge-to-jump
http://pimediaonline.co.uk/science-tech/lappel-du-vide-the-call-of-the-void/
Thank you! I'll check them out.