You had been on a high dose of Effexor XR for 2 years and you should taper it off over 3 weeks time instead of 8 days and watch out for discontinuation symptoms even after the withdrawal. Anyway you are over with Effexor XR. Effexor is an SNRI while Lexapro is SSRI. But they are more or less the same with regards to classification, efficacy and side effects. Lexapro claims to be an improved formula of Celexa, which is another SSRI. The pharmaceutical companies that launches these products tends to include an exhaustive list of possible side effects from the established papers to safeguard themselves from possible litigation. Remember each paper reveals its own profile of untoward effects from its set of patients. If you look at that list, one will probably be scared and shy away from the drugs. By and large, SSRI are much saver than older antidepressants like tricyclics and tetracyclics. If you know how to use your drugs or take them according the advice of a psychiatrist, these drugs work wonders. If you quit it in 8 days instead of 3 weeks it makes you hate it. And everyone has a idiosyncratic interaction with a certain drug which may not be in the literature. So, step up Lexapro slowly and taper off in 3 weeks time for stopping it. Or if you are scare of SSRI, you can try another class, e.g. Wellbutrin.
What you described seems to be true of all the antidepressant medications, and especially those ssri's. You have to wean carefully once you have been taking them as long as you have, and at the dose you have. And you have to make sure your underlying depression is resolved, not just dampened down, so that does not reappear. Its best to be in therapy and take mediations, and gradually diminsih your medications. Lexapro is a little less likely but you will stay have to wean yourself carefully.