More code please, especially what type dx, dy are.
Here is the rest of the class. I'm still learning so please ignore the dirty code. I was playing around with switching everything to vectors as well so ignore the unused variables!
dx/dy are floating points.
As far as the "move extremely fast to the tile clicked" issue...try doing some research on delta-time for game development.
I'm using delta time already.
The sprite actually moves one tile at a time now, it just only moves in a negative direction. I took a break from the code. I'm going to go through it again and try to figure out what i'm doing wrong.
*EDIT* I actually got it working. I had it setup incorrectly. Here is the new pastebinhttp://pastebin.com/yY3UMDUz