The Consequences of Choices
I was thinking more about your claim that life was just a game to you. I can see how it appears to be a game to you. You've been playing hide and seek with your family and friends, trying see how much you could get away with. So far you avoided accepting responsibility for your choices. It isn't that those consequences aren't there, but it is sure easy to pretend they don't exist when you don't have to deal with them today.
Asaph saw this in the wicked: "And they say, "How does God know? And is there knowledge in the Most High?" Behold, these are the ungodly, Who are always at ease; They increase in riches" (Psalm 73:11-12). He was tempted to give up godly living because of it. "If I had said, "I will speak thus," Behold, I would have been untrue to the generation of Your children. When I thought how to understand this, It was too painful for me- Until I went into the sanctuary of God; Then I understood their end. Surely You set them in slippery places; You cast them down to destruction. Oh, how they are brought to desolation, as in a moment! They are utterly consumed with terrors" (Psalms 73:15-19).
A seeming lack of immediate repercussions doesn't mean they don't exist. Smoking will bring about cancer, if it doesn't cause you to die of something else first. It is a simple fact. You're young, but I can already hear the wheezing in your lungs. You see, life has rules. You walk off a cliff and you will get hurt -- it's the rule of gravity. You fill your body with poisons and damage will happen, even if you get high while poisoning yourself.
Is there a difference between committing suicide rapidly or slowly?
Satan fooled Eve when he said, "You will not surely die" (Genesis 3:4). It probably looked like he was right at first. She didn't die physically that day or for a long time thereafter. But death was introduced into the world when she ate and she did die.
Don't let Satan, through smoking, fool you too.
I'm praying you return while there is still time for the damage to heal -- both the physical and spiritual. I want you to have a beautiful life.