Celexa and tiredness

I have been on Celexa for a little over a week for panic attacks/anxiety. The first 2 days I took it I felt like I was in a dream, light headed, tingly, pretty much just intensifying my problems in the first place so I stopped taking Celexa for a few days.. then I spoke with my doctor and she said to try taking it at night instead of the morning. So I began taking Celexa at bedtime. I didn't have much side effects except for a little trouble sleeping, but I actually was starting to feel "better", for about 4 days I was feeling really well and resuming normal activities. Then out of nowhere on that 4th day in the evening I got a really bad panic attack, and for the past 3 days since I've been feeling high anxiety and panic again. I don't understand, because I really felt like I was getting better. I told my doctor what has been happening and all she said was that its normal to have set backs and to continue the Celexa. I'm also taking Ativan to help control the anxiety until the Celexa "kicks in", but in the past few days nothing has been seeming to help. Has anyone experienced this? Is it because I've only been on Celexa for a week? I feel like I am going crazy being back in this lightheaded fog.

Ive been given citalopram for depression and Bulimia.
The side effects I experienced were:
Nausea
Thoughts of suicide
Tiredness
Loss of concentration
blurred vision
diarrhoea

although most of these symptoms stopped after taking the citalopram for 2-3 weeks.

I generally feel less depressed than i used to be, although my eating problems are still here