Hello there,
How long have you been taking Zoloft and Celexa? Also note that Xanax should be used when having a panic attack or as a short-term treatment of anxiety. A long-term benzodiazepine to use would Klonopin.
Antidepressant may take up to a month until you see any improvement. If they don't work you can try another kind of antidepressant. Those you are taking are called SSRI which means selective serotonin reuptake inhibitors. They affect serotonin which is a neurotransmitter related to happy mood and such. Another kind of AD you can try if you see no improvements at all is a SNRI; selective serotonin-norepinephrine reuptake inibitor. It will affect your serotonin level and also another neurotransmitter called norepinephrine. Norepinephrine transporter normally recycles some dopamine too, then SNRIs will also enhance dopaminergic transmission. Therefore, the antidepressant effects associated with increasing norepinephrine levels may also be due to the concurrent increase in dopamine.
You must also consider having a healthy diet ( good intake of nutriments ( vitamins, minerals, protein, carbohydrates, lipids ) ). Also consider exercise. Exercise is a natural antidepressant. It acts on the brain and body by balancing your hormones. When doing physical activity you are producing about 8 hormones that are essential for healthy mind-body. The endorphins for example ( an opiate produced from the pineal gland ) will relieve tensions, decrease pain, but will also affect your moral. Other hormones produced by doing exercise are insulin, thyroxine, growth hormone, testosterone, estrogen, epinephrine, glucagon. Those are all good for you and having good balanced hormones will help your brain and as well you body.
For more information about the benefits of nutrition and exercise for mood disorders you can read my post dedicated to the subject:
http://www.medhelp.org/posts/Depression/Knowledge-for-Depressive-People/show/1127539
Best regards,
M4