Heh... haven't been through something exactly like that... but I dated a guy for a year... became real close... married... and a year after we were married, he started acting bizarre and controlling. It wasn't until much later I figured out he was a sociopath...
So yeah... it happens. Would imagine that's how women enter into abusive relationships --- they find out later the guy is off his rocker.
"The weakest soul, knowing its own weakness, and believing this truth that strength can only be developed by effort and practice, will, thus believing, at once begin to exert itself, and, adding effort to effort, patience to patience, and strength to strength, will never cease to develop, and will at last grow divinely strong."
- James Allen