Anticipation. Giving up negative thoughts and hurtful comments

As a comedic genius, many of my jokes and simple jibes at my friends, often at their expense. I often make this simple negative quips that in my mind, pass by harmlessly.  These negative jokes, as I know see, are the lowest form of joke, the cruel joke. Along with these negative jokes, I often find myself thinking negative thoughts and stressing about moral, ethical, and material dilemmas. I realize that this pessimistic view might not be the best one for me, therefore I should think positive. Every time I think something negative, I will think the opposite instead, and see how that affects my week.