Cover bottom of 9x13-inch pan with crust ingredients and press into the pan.
Mix cream cheese and confectioner's sweetener and add melted butter until smooth.
Spread on top of crust.
Mix strawberries and banana in medium bowl with lemon juice.
Spread strawberries and banana mixture over cream cheese mixture.
Make stabilized whipped cream. Soften gelatin in water and then pour it into the heavy cream, vanilla extract, and sweetener. Use an electric mixer to beat at high speeds until it is combined. Spread this topping on the cheesecake.
Top with chopped nuts and chocolate sauce if desired.
Video
Notes
To keep the carb macros low, don't use very many bananas. Since you are spreading out the bananas over the entire cheesecake, each portion won't have very much of this high-carb fruit in them. To lower the carb amounts, use fewer bananas or replace bananas with all strawberries or another low-carb berry.