I was on lexapro (escitalopram). how long do these withdrawal symptoms last and will i ever feel happy again?

Drugs like lexapro (escitalopram): should generally not be stopped abruptly, but should be tapered over several weeks. If you were on 20 mg per day, it should be reduced to 10 mg/day for a week, then 10 mg every other day - that usually will stop the withdrawal symptoms. Depression can be a lifelong disease, and both psychotherapy and medication may be helpful. Many people achieve remission, but it takes work and expert help.