WHY DO WE FALL IN LOVE?

I’m a confused teenager

I have a crush on someone i don’t deny it but i’ll let it be more than that i feel like falling in love is like letting your guard’s down and I CANT do that not yet!! 

I also think i have serious commitment issues so why would i be with someone just for us to hurt each other? sometimes i think my way of thinking about relationships is because I didn’t have the best dating experiences but some people still fall in love after getting out of a very abusive relationship which always makes me wonder HOW?