Is it unusually?

I'm 16 and I wanted to know if it was unusually for me to think about sex at this age or Crave sex? I was just wondering

The feelings you're having are your hormones becoming active. That's perfectly normal as long as it doesn't start having serious effects on your behavior. The teenage years are a time when you have to learn to control your emotions. It's learning to do what makes logical sense rather than what you feel like doing and sex is only one of the areas where that emotional control is necessary. As long as you can deal with your feelings (masturbation is OK) without risking your future by becoming pregnant or catching STD's you will be fine. If you are thinking of taking such risks, that means you aren't gaining that emotional control and you should talk to a counselor or your parents about it.

What is more unusallly is your lack of education.
Make sure you read books in between copulation my friend.

Yes it is very normal.
You need to study a little about "Human Growth Development." dealing with this. It's a amazing to learn about it. You also can watch Youtube videos.