I got similar problems when upping Lexapro when I was on it, and got problems going down, as well. Seems to have a big bit even with small changes in dose. It's only been a couple of days, so it might pass. If it doesn't, it just might not be your med, assuming you don't have some new issue -- but I would argue that, even if you did, if the Lexapro isn't dealing with it, it isn't working very well. That's what drugs are supposed to do, after all -- artificially tamp down our symptoms, given they don't cure us. Just because you're on a med doesn't mean you give up working on the issues -- I made that mistake, and it availed me not.
Have you had any other factors that could be causing your anxiety to spike? Are there additional stressors besides the medication dosage. My anxiety would peak whenever I would adjust the dosages of SSRIs up or down for a couple of weeks. Are you in counseling? Why not express your concerns with the person that manages your medications? I know it can be very confusing when we suffer from anxiety especially when dealing with medications.