My terrain doesn't give feeling of 'height' from above .

First off , this is what it looks like from the distance of around 1 KM height

And this is what a popular game like DCS looks like

Those two low poly mountains from the asset store are about the height of 1.3KM . The dimensions of my terrain are 50KM * 50 KM and 2KM in height . The height is max . around the edges ( to hide horizon ) .

I'm using a Photoshop generated height map ( 1024 X 1024 px ) which is applied over this entire terrain at one go . There is only one texture applied on the terrain which is also of size ( 1024 * 1024 px ) .

I just used the height-map to generate color based on the height values in photoshop itself ( green color for valleys and blue-greyish for peaks ) .

Now there are several problems which have accumulated with this setup

• It doesn't feel like I'm sooo above the ground , that vertigo feeling doesn't appear . Now I understand that there are less visual elements on the screen , but sill in games like DCS even with a flat plane with nothing but grass it gives the feeling that you are actually that much above the ground

• My terrain brush has become a big square ( at 1 size) . I am unable to paint any new texture . It just all blurry one colored ( for eg. the brown color near the mountain is actual brown bumpy grass texture but now it just appears as a low poly brown color on the terrain ( even close up ).

• I have turned off automatic lighting generation and it says it' will take around 3 hours to complete when turned on .