(not an instructor)......Aim Point and Contact Point are not the same. when you find the intended path of the object ball, you can imagine a line going back through the object ball, and coming out the back of the object ball, but you do NOT aim at the point where the line exits the object ball (that would be the contact point, but NOT the aim point). You have to extend the line another half-ball diameter further back for the aim point (this would end up being in the center of a "ghost ball" that is also in line with the shot.
Of course many times this aiming point will be entirely outside of the object ball (to the right or left of the object ball).
I have added two "stars" to your drawing.
The one to the upper right is where to aim if you wanted to make your original shot (your black line). The lower star is where you really did aim, which would move the object ball along your "yellow" line.
Let me know if this helps....good luck...