When I was on Lexapro, I consulted their website. It recommends 20mg for anxiety, 10mg for depression. Not that this is set in stone, as stated well above, but it's something.
Don't worry about your dosages. Leave this up to the doctor and let him/her decide what's more appropriate for you. Tell the doctor exactly how you feel and what you are experiencing.
Take the pills as prescribed and don't give it a second thought.
Everyone is different when it comes to medication. What's good for one may not be for another. Concentrate on things other then your every feeling and worry. Try to keep your mind occupied with other things and try to have a positive outlook on the future and give the medication time to make all this easier for you. Good luck.