I've been on Lexapro for 3 1/2 months. When I first started taking it (10mg/day) my stomach felt horrible. I had all sorts of stomach pains. But I was already having stomach problems before that so that may have been part of the problem.
I also had night sweats. Later it was mostly my palms and bottoms of my feet - how strange and creepy! I felt like the creature from the lagoon.

LOL
The other side effect from lex was a strange heavy feeling in the back of my head. It was like the two halves of my brain were not functioning properly and had lead weights in the back.
It took me almost 2 weeks for the side effects to calm down. Then after three weeks the medication finally started to take effect. It did help me get past my initial severe case of GAD.
Now I am trying to wean off it. I'm am holding steady at 5mg/day. With the lower dose I am feeling almost completely normal now. Not so groggy and lethargic as with the higher dose.
But I have some minor anxiety and other feelings. Not bad, more like normal everyday life.
I will continue for another month at half dose as I continue to learn and practice my CBT skills. Then I'll go down to 1/4 dose and see how I do.
PLEASE, anyone reading this, if you haven't started taking Lexapro yet, if you are able to manage, try to work through your anxiety by getting lots of vigorous exercise every day and cutting out all caffeine and sugar first. And also work this course, you should be able to cope without going on the drug. If you just absolutely can’t cope, it's ok to use Lexapro but it’s much better in the long run if you get by without it. That way you can avoid the troublesome withdrawal period. And you will be much further along in your recovery process later on.
Do your research. Google Lexapro and do a bunch of reading BEFORE you go on it so you can make an informed decision about your health care. Do just take your Dr.s word for it. They get paid by the drug manufacturer for subscribing this stuff!