I grew up relatively poor, in a small town (800 people), didn't do that great in college, went to a no-name college in the midwest. I used to think like you "How will I ever compete"

And then I started to meet people the exact opposite of who I was. I realized they are just like me, and there is nothing to be afraid of.

If you're motivated and half way intelligent you'll be fine. Things probably won't turn out how you expected, but you'll be okay.