has lexapro worked after it worked a first time, but didn't the second time?

I will try to be clear.

I started taking 5mgs. of Lexapro for panic disorder in 2007. It worked for me overall. September 2008 I stopped. I thought I was ok on my own and I was gaining weight. By December 2008 I was panicky and probably still not all the way over the withdrawls but it seemed I was or should be, who knows. So I started it up again and it made the anxiety worse. I was directed to take more, so I did slowly (did before I was told, as I knew what they were going to say). But the more I took, the more nightmares I got, more suicidal and more panic attacks, so I quit. Again. In April 2009.

It's October now and I have needed something else for a few months now. I have been taking Xanax on and off since 1996. Before, it was occasionally, but now it's daily, and I take Benedryl with it to help it along a bit. Pieces of it, that is.

I was able to not take SSRIs all this time (before 2007), but now I feel this latest bout of constant anxiety isn't going away as I had hoped. The dr. wants me on Zoloft, but I have read of it being stimulating and a sort of "nervous" med. I want no part of that, as the start up side effects scare me badly anyway. I can't seem to find a med that others seem to tolerate well or AS well as Lexapro.

So the question is: After being off Lexapro for about 6-7 months, is it worth it to try it again or will I end up with the bad effects again? Has anyone been able to retake a drug that worked for them once, but not a second time, after some time has passed and the body was able to sorta get back to where it was before the SSRI? I have read online that it can take a year for some SSRIs to get out of the system completely, leaving some side effects behind, so to speak, that we wouldn't attribute to them. ?

Thanks!! I really need some input here.