I see this post is pretty old, however - I've been on citelopram (generic celexa) for about 5 months now, and I did notice a jump in anxiety for the first week or so. I also had some very rough stomach issues that came along with it. However, I am very pleased to tell you that it is doing a great job since then. I've only had 3 (count em, 3!!) bad days since I've gotten on it, and I feel pretty darn close to my normal self!
Here is a great guide a guy wrote about his adventures with citelopram. It more or less walks you through everything you could want to know first hand about this med. Keep in mind, this is just one guy's experience with it, but he's pretty well researched and he always puts a positive spin on life with anxiety meds.