Anxiety / Numbness / Burning Legs

I'm a 33 yr old male. In October of 2007, my the fingers began to get numb. The numbness was not centered on one particular finger or fingers and varied in duration from day to day.  At first I attributed it to a flu shot I received days earlier. I began to get very panicked over this and began to feel burning/crawling sensations in my legs as well.

My doc at the time ran blood tests and order a MRI on my brain all of which came back normal. A neurologist also concluded nothing was wrong with me and a nerve test on my hand came back negative. He order a round of elavil which didn't do anything except get me foggy in the head.  Around this time I began to have trouble sleeping and after my original doctor refused to help me, I went to another doctor who prescribed ambien and advised me that lexapro may help.

Eventually, I was able to get down to 2.5mg - 3.3mg of ambien to get to sleep while starting the course of Lexapro. After 6 weeks I was advised to move up to 20mg of Lexapro. For several months afterward, my anxiety all but diminished, the crawling/burning sensations were gone and my left fingers would become numb less and less (although they were never numb free).  I did have some days early on of isolated odd burning spots on my left knee and outer right thigh as well as numbness in my toes but over time  these went away.

After gaining 15 pounds and losing libido, I decided to get off the Lexapro around Oct 2008. I took two months to taper off and took my last dose on 11/22.  About a week later, I got slight feelings of anxiety and about a week after that my hand numbness and burning legs were back in full force.

Deciding that the hand and legs may be attributed to nothing but anxiety, I got back on the Lexapro on 12/26 @ 10 mg and recently increased my dosage to 20 mg on 2/11.  My hand numbness has settled down (but still hasn't went away) but the burning legs are still there.  Because I thought getting back on the lexapro would get rid of the burning legs, I am considerably distressed.

My doctor wants me to start a course of Xanax XR for two weeks to let the 20mg Lexapro kick it but I am very reluctant to take it because of the horror addiction stories.

anyways...my questions are:

1) Is it entirely possible that the burning legs are nothing but anxiety or could there be another physical cause I should get my doctor look at?

2) Is it possible that the Lexapro won't ease the burning legs the second time around?

3) Should I take the Xanax XR for a couple of days to see if the burning legs go away? How long can I take it and still be able to stop cold turkey and not have withdrawals?

4) Is there any other remedy I can take that can ease the burning legs symptoms?

If I could just get past these legs I'll be alright.

Thanks