Janey- I don't know your medical history as fas as anti-depressants are concerned; however, if you've never been on meds and are suffering from anxiety(with DP) I think that you should first try a benzodiazepine(Valium, Ativan, Klonopin). These medications will calm you down and will allow you to function again, but they're not meant for long term usage because of habit forming potential. The reason your anxiety is so out of control is because all of your symtpoms are building up and feeding of each other and it feels like they're cascading and getting worse, and the problem with Sertraline and othe SSRI's is that they will make you feel uncomfortable in the beginning; they take two or three weeks before they work in your system. I tried an SSRI once for a couple of days and it made me extremely nervous, so I stopped.