You are fine, you aren't and won't go crazy, I promise. What has happened is you stopped your Celexa for two weeks cold turkey, you never want to do this. Your symptoms have returned along with some withdrawal. It's the withdrawl feelings that are new to you. KNOW that this is NORMAL in this situation, tough, but normal. Your body and mind are reacting to the drop of medication in your systrem, as it builds back up you will feel better as you continue on your Celexa. Do deep breathing exercises to calm yourself down as much as possible. I know it's scary, but you will return to normal shortly, and keep telling yourself this. Try to stay strong and never stop your medications abruptly like that, it causes very bad withdrawal symptoms as you are experiencing now. Be strong, know you are fine, and will get better. Stay with us for support if needed. There are many here who can share their stories of withdrawal from stopping their meds abruptly. Take care and come back as often as you want.
You say you came off ur med's and now your back on them, it may be possible that ur body is readjusting to the celexa as now four days later the drug would of built up in your body. this may be one cause, if so it will pass with time and should not stop taking it due to this...you will be fine.
As for the crazy feeling...trust me you will not become schizophrenic or psychotic, many a person has felt the way you are right now and yes it does feel like your going to slip over the edge to insanity but this very raely happens. Anxiety, severe will stop you from eating even out of blue and so this is normal.
Because of how bad your feeling maybe you should get in contact with your local mental health team, hospital and tell them as they are there to help in times of crisis, they may give you some anti-anxiety med's just to get you over this hurdle...trust me they help!! I have been exactly where you are right now and i know it anit pretty... just hang in there and contact them if you feel like your gona do something silly like harm yourself.