I completely agree with Paxiled. Your Dr. should have known better.
That taper is too fast. Your doctor doesn't know about how to do this, which is common for primary docs. Psychiatrists who aren't very good still usually taper off for 6 weeks these days, but the rule is, you taper off as slowly as you need to, not as slowly as someone else might need to. Generalizations are harmful here. You have two alternatives: Go back on the Lexapro at the last dose at which you felt fine and taper off as slowly as you need to, or stick it out and hope it stops keeping in mind that some people suffer very long withdrawals and some very short ones and some none at all and some permanent ones. We are different. If you decide to stick it out, try taking a good dose of fish oil every day -- some say it helps with the zaps. My one big piece of advice is, if you notice that the effects turn from just being physiological to new emotional problems you never had before go back on the drug. And next time do this with a psychiatrist you've quizzed beforehand on whether they know how to do this properly and carefully and individually.