i think most of your problem is mental. however some tips would be try toe edge pressure off the lip, not enough to turn the board, just to be on the balls of your feet and in an athletic stance. next grabs really help with staying balanced in the air. also gives your brain something to think about besides an arse first landing. and last i would drop down to a smaller jump to get the confidence up. a straight air is a straight air is a straight air. good form on a small jump will translate to bigger features.