Also, keep in mind that it takes time for the lexapro to get really good and balanced in your system. I just went from 10mg to 20 mg at the beginning of April, and it took a good month before I noticed some leveling out of things. I did notice the med change right away (it actually made me almost manic), but it has taken this long for me to settle back into an even keel.
Give it some more time; it could take 6 more weeks or so.
Also, I agree with the pp. Talk therapy can also be helpful. I do that too.