This may be easier using the hand opposite the breast you are using. (pregnancy-info.net)
A variation on the cradle hold, the cross-cradle or crossover hold involves the same positioning except you support your baby on the arm opposite the breast being used. (healthychildren.org)
• With the hand opposite the breast from which you plan to nurse, place your thumb and forefinger behind and slightly below your baby's ears, so that your palm supports baby's neck and upper back and his trunk rests on your forearm; tuck him in close, tummy to tummy. (nurturenormally.com)