Why do I feel so lost and confused?

I'm only 13 and I know that these type of feelings are normal at my age. But It's just been haunting me lately. Why am I in this world? What is my purpose? These are the questions I ask myself everyday. I know finding an answer to them is almost impossible but that's why people turn to religion right? But I can't help but feeling so alone and lost. "I'm just gonna die and that's it." it's all over. I choose to believe in heaven and god, but I've just been thinking "What if there is no such thing? Will there just be eternal darkness?" I'm in a place of confusion and I don't know how to snap out of it. I feel like I'm going insane like these thoughts will never end. I just want to feel some kind of normal. Like this is how life is. Like everything is going to be ok. I'm just lost in what to think. My mind just doesn't comprehend these topics.