It is a little hard to understand the exact question since English is not your native language. (It's OK! We're just trying to understand and appreciate your difficulty with the language.) 'Thickness' would suggest horizontal stretch lines as Dwight suggests. "Too High" suggests that you are talking about vertical height (vertical stretch lines).
But do note: you cannot make a wall shorter (height) or thinner (width) than the profile. So, you may need to reduce the profile itself to decrease the thickness.
Put another way - the vertical stretch lines (if placed, and enabled by the check box) can only make the wall taller than the cross section in the editor, never shorter. Similarly, the horizontal stretch lines (if placed, and enabled by the check box) can let you make a wall wider (thicker) than the profile - but never thinner.
Cheers,
Karl
