Am I going crazy?

I honestly think I'm going crazy. I realized for the first time that I actually scare myself sometimes. I get these thoughts of things I want and think I need that contradict everything I think I am. Is it possible that these thoughts and ideas are who I really am? Is it possible that I'm just trying to convince myself that I'm not that person because I don't want to be a bad person? Or is it all in my head? I feel like a crazy person sometimes. All this stuff going on inside my head that contradict one another. So many things running through my mind all at once. How is that possible? Am I the only one? Is there something wrong with me? Am I going crazy? 
I keep telling myself it's just in my head. The depression, the lack of self-confidence, the not knowing who I am, keeping people away, not trusting anyone, wanting all these things that I can't have. I thought it's in my head and I just had to figure out a way to overcome it all. What if it's not that easy. What if there's something going on with me? Mentally or physically or something I don't know? Is it possible? 'Cause the more I think about it, it just doesn't seem right. It doesn't seem normal on any level. But then again what if I'm overthinking all of this.
It seems like every single thing I go through these days I think about exactly like that. I think it's one thing, but then I start to doubt myself and say no that can't be right, and it just goes on and on and on and on in my head. It happens almost ALL the time and it's giving me constant headaches and it's driving me insane.
Is this normal?