Here's your opening sentence. It raises some interesting issues regarding verb tenses.

I'm not a believer and I certainly don't believe in fate, but the moment I pushed aside the flap and followed Lucy into that tent, I knew things won't be the same.

The sentence is wrong, but it's not immediately clear which way it is wrong. Consider these two variations:

I'm not a believer and I certainly don't believe in fate, but the moment I pushed aside the flap and followed Lucy into that tent, I knew things wouldn't be the same.

I'm not a believer and I certainly don't believe in fate, but the moment I push aside the flap and follow Lucy into that tent, I know things won't be the same.

Either variation is correct, but it's an either/or choice. Cast the narrative voice in present tense, or past. But not, as you have done, both, indiscriminately. Given that the majority of the narrative that follows is in past tense, I'd say you should go with that. Go through and root out the other lapses into present tense and fix them. It makes you sound like a clumsy rookie, and you certainly aren't. I'll point out that the opening phase in all three versions remains unchanged, spoken in the present. One assumes that a narrative in past tense is being recounted from a point in time subsequent to the events under discussion. Thus, such a generalized statement concerning the narrator's world view establishes context and is correct in a sentence that otherwise is cast in past tense.

So much for the nuts and bolts stuff. The reason I spent so much time with the issue is that, rookie blunder notwithstanding, you otherwise have a nice tale going on here and a genuinely mature prose style that allows you to get away with an approach that a lesser writer would stumble over. (One other thing you might want to do is pay attention to the difference between your and you're. You confuse them at one point and once again it's needlessly shooting yourself in foot, sounding clumsy when you aren't at all.)

If I have a structural complaint, it's that I'm not sure you've made a sufficient case for Lily's drastic action at the end. I realize she recants and tries to undo the deed, but that she would take such a step in the first place seems to require a bit more in the way of disappointment, anguish, frustration, perhaps anger. But we have to merely assume she's gone through those steps because they've all seemingly taken place off stage, outside the bounds of the story narrative. I'd figure out a way to show more of this process, making it unnecessary for your character to spoon feed the information to the reader. Let them see her in the midst of her condition, they'll sort it all out for themselves, and have a much more satisfying reading experience for it.

Still, it's a nice bit of writing. Fix the simple stuff, spend some time thinking about the aesthetics, and you'll have something that could easily find a place in the market.