If you fudge turns out shiny, you likely overworked the cashews and released the natural fats. Next time make sure your cashews are room temperature (not cold), that you don't grind them too much, and you are careful to not overwork the dough. For kaju barfi that seems sticky, it is possible that the sugar did not cook to the right consistency when cooking the dough. You will need to cook for a few more minutes. You also might want to add a bit of evaporated milk powder as you form the dough if it is still too soft. Sprinkle in little by little until the dough reaches the perfect consistency, making sure again to not handle it so much that fats are released.