There are a number of things that could be causing you to index the front sight high and to the left of the target, and contrary to what you've read it's basically impossible for people on a forum to diagnose what you're doing wrong.
The problem is that it could be any of these things:
- Your strong hand grip is wrong
- your weak hand isn't making contact with the gun correctly
- your hands are coming together too far away from your body
- you're bowling the draw
- you're rushing the draw
Sounds to me like it's time to take a class.