Giving up is it the thing to do?

Do you ever feel like the world has turned it's back on you and no matter how hard you try you can't seem to make things better. Do you think I just need to give up everything that means anything to me and stop the fight? I really do need some advice on this. Why are people so thoughtless and mean to others? I really don't understand this and it can cause a person to just stop dead in their tracks and say is it worth going through all this pain and agony for something I have no control over. What should I do ? I know for a fact I'm not mental just hurt. How can people play with someones emotions and sleep good at night?