You went off Prozac? When? Did you slowly reduce your dosage?
I ask because when I chose to stop taking it, I experienced SSRI withdrawal symptoms that included depression and suicidal thoughts. I knew it was the SSRI because I had never experienced depression or been suicidal before nor since then. I was also experiencing myriad other withdrawal symptoms including minor hallucinations and strange body sensations at the very worst of it. Your feelings right now could be temporarily induced by withdrawal symptoms, too. I did not return to normal for at least 2 months and I wasn't sure if I would survive that time period. It was one of the most frightening experiences in my entire life.
Please consider the possibility that your feelings right now have been caused by Prozac and that you may feel overjoyed in a few weeks that you waited because your enjoyment of life returns and you have so much to live for and experience and you don't really want to end your life.
SSRI discontinuation syndrome - Wikipedia, the free encyclopedia
Antidepressant Discontinuation Syndrome - August 1, 2006 - American Family Physician
SSRI Withdrawal Procedure: Getting Off Antidepressants May Be Made Easier
SSRI Stories
EDIT: I just reread that post. You quit Prozac 3 weeks ago? You ARE having withdrawal symptoms! You can't just abruptly stop taking them! It causes a serious drop in your dopamine levels and your brain ceases to function properly. I remember that I felt like my reasoning was perfect. Perfectly rational. And everything seemed crisp and clear, beautiful to look at, but cold and empty. And I had no motivation. Not for anything. Nothing seemed worthwhile and my life felt pointless and I could make no argument for living that was convincing to myself. Except for one: that maybe the way I felt would be over in a few weeks, and I wouldn't feel the same way anymore. That's what got me through it, the conscious realization that my mind was addicted to a drug and these feelings and experiences were a part of getting over that addiction and it would all be worthwhile after all. I was right about that. You have no idea who glad I am that I realized exactly what was happening to me and I chose to endure it until it was over, which I remember was hard. It was hard to do. Some minutes felt like they would take forever, but I held on to that goal of getting through it, just to see if it was all an illusion caused by that cursed drug Prozac. You can make it through this, but please find someone who can help you with it. Please. You'll be so glad you did.
This is extremely good and extremely important advice, and really worth considering and taking seriously.