Why do we have emotions?

I'm not looking for "to help prepare us for things the world might throw at us" like fear or sadness. I dont want to know they help us cope with the world. I want to know WHY we have emotions. What makes us have emotions. Just as anything else in the body funtions (ex: our heart beating without us telling it to physically, or breathing without telling our brains to suck in air constantly), why does our brain instill emotions into us all? What does it? Why the EFF do I feel like crap?!?! Son of a B..... this sucks...