When we go up in the atmosphere we feel the pressure, when we go down in the water we feel the pressure then why don't we feel the pressure on ground level- physics

Because we evolved to suit the air pressure and gasses and gravity that exist at ground level of the planet. There are some sea creatures who can survive both great depths and surface water, such as lobsters.
Pressure under water is from the weight of water, very different from what we feel at high altitude, which isn't higher pressure at all. It's lack of oxygen.

What you feel when you go under water of to high altitude is the change of pressure relative to what your body is acclimated to. When you dive under water the external pressure on your body is greater than the internal pressure and so you feel uncomfortable. But if you stay under water for a significnt period the pressure becomes equalized, and the discomfort goes away. Then later if you return to the surface the change in external pressure again causes discomfort, this time because the external pressure is less than internal. If this change occurs too quickly it can lead to a painful and possibly deadly condition called "the bends," in which bubbles of nitrogen gas form in your blood stream as nitrogen comes out of solution of your blood serum (much like CO2 gas bubbles appear when you open a bottle of carbonated soda). When flying in a plane the decrease in air pressure compared to sea level can also cause discomfort such as popping of ears, but since the change in pressure is at most one atmosphere there is no significant danger of injury.