I've been on
Lexapro for several years now and my doctor put me on it when I had gone to LA pain meds. I started with 10 mg and then went to 20 mg. To be honest, I have not heard of anyone being on 30 mg. That doesn't mean it isn't done every day. There are always people on higher doses of meds than we are.
If I were you, I would go ahead and give it a try for a trial period of time and see how you do. How it makes you feel. You can always go back to 20 if it doesn't seem like it's needed or doesn't feel right for you.
Good luck with it. I'm glad you're doing better on the antianxiety meds.