The fact that you are feeling calm is a good sign that the Lexapro will probably work well for you. Sometimes ADs can worsen anxiety before they make it better. You aren't an emotional zombie, you might just be starting to recover from an anxiety disorder, which would explain a zombie feeling as in my mind, going thru and anxiety/depression disorder is very traumatic, so it takes time and, usually, medication and therapy, to process having gone thru it even when you do start to feel better. And of all the people I have known who take/have taken antidepressants, and as Ian says there are probably many more people I know who are taking ADs but don't mention it, none have become homicidal maniacs. That isn't going to happen with an AD. Either is doesn't work or it works, with or without side effects that may or may not be annoying. But your worrying about what it can do to your mind is a symptom of your anxiety, not the medicines. Plus I would assume you keep in contact with your doctor and, if you have one, a therapist. If you shared your concerns with them, they would no doubt put your mind at ease.