Easy Sugar-Free Dessert

1 (6 oz.) pkg. sugar-free Jello
2 c. hot water
1/2 pkg. Crystal Light lemonade mix
2 c. water
3 c. Cool Whip
1 angle food cake

Dissolve Jello in hot water. Add lemonade mix and water. Chill until slightly thickened, beat until frothy and fold in Cool Whip. Fold in cake broken in pieces. Put into 9 x 13 inch pan and chill.