Of Whom I Am the Worst

I am filled with bitterness and anger. It has controlled my life for months now. I am angry towards Josh, my ex. He broke up with me right before summer break last year. He said we could be friends again this year, so I came to school expecting that would happen. I found out that he was just saying that because it's the proper ex-boyfriend thing to do. He would only talk with me or acknowledge me when he was around people that he knew we had mutually in common. Otherwise, he would pretend I wasn't there. As a result, I treat him as if he doesn't exist. I am so bitter. I want to hurt him. I really do. I want to make him feel as shitty as he has made me feel. I have let him have way too much power over me. Now every time i see him, even just in passing, my stomach ties in knots and I feel anger swell up inside me. Every time. And I'm tired of it. I should be able to forgive him. He hurt me and he has continued to hurt me, but me acting the way I am does nothing but make it worse. I'm just hurting myself even more by doing this.
I just recently dated an atheist. It was great, except for the fact that he made me doubt and second-guess God's existence. Not that that's bad. In order for a person's faith to grow and strengthen, they much doubt. Asking questions and feeling hopeless is necessary to truly finding God. The only problem is... I can't find him.
I used to be so strong; so on fire! I was a leader in my youth group. Everyone in my school knew I was a Christian. I had problems, sure. I started cutting myself and developed an eating disorder. but as for blatantly acting out, doing drugs, going to parties and whatever else highschool kids did, I didn't. When my friends had a problem, they came to me. I was so in tune with God. He was everything to me.
And now?
This intense disbelief in my Creator and the bitterness and anger that has been ruling my life has brought me to this point. I have been dwelling in anger, sin, and hate. I feel so utterly alone and lost; hopeless. I think about the tattoo on my shoulder of "hope" and I wonder what it was like to at least have HOPE that everything will be alright; that God is still with me.
I know God is real. He has to be or nothing makes sense. But I don't know how to find him again. When this all started, I fervently prayed that God would show himself to me. Let me know that he was there, that he was real. Somehow make me know! I prayed that over and over again, tears streaming down my face.
Nothing ever happened....
I haven't prayed since. I guess I have, every once in a while. "I haven't talked to you in a long time but if you're there, I'd still appreciate it if you'd show me." Why wont God, my Creator, my Healer, my Lover.... why wont he reveal himself? I've been praying that prayer for years. So where is he?
I am so lost. I am so full of anger and despair.
Where is God?