Can't hit irons off fairway

So at my local club there is a net sort of thing with a grass mimic thing on the ground. I feel as I can hit most shots on it quite nicely but feel like it is quite unrealistic. I tried lot's of shots on the golf
course and about 15% topped 75% hit low ball flight (thin) 10% fat taking a massive chunk of ground. Not even one good shot. I tried to put my shoulders to the left as-well as my hips to try and go down on the ball but it doesn't work. That Can't hit irons thread doesn't help me and I'm 12.