It's not a sin. Ice cream tastes great, how can such a thing be a sin? Next time you eat ice cream, instead of worrying, think about how enjoyable it is, how good it tastes, how satisfying the flavor is. Enjoy all of these things fully and without self-deprecation. If you view the act as a genuinely pleasurable activity and not something dirty, you will develop a better relationship with your ice-cream eating habits and be able to regularly eat and enjoy a stable and calorically acceptable amount of ice cream without worry or regret.
That's what makes it good!
You killed the cream??!
It's because you don't deserve it.