He needs to see a doctor.
Going off lexapro cold turkey can cause a psychotic break, brain damage, and death depending on the dose & his neurochemistry.
CALL HIS DOCTOR (dont wait for husband to come home from work) and tell him what's your husband has done & his behavior.
It may be that your husband was on a low enough dose that its not life threatening, or that he squeaked by in the minority of people who could make it to DayXX without snapping.... And past dayXX hes just fine. BUT...only his doc will be able to say whether he needs to go to hospital by ambulance or that he'll be fine, just cranky & paranoid for a few days, ride it out at home.
_____
Why am I so intense about calling his doctor this very minute?
My girlfriend did the same thing, by the by. After a few days she took scissors to her lingerie, hair, walls, furniture... And swallowed d dry pill in the house, before calling her boss to swear at him nonstop. Thankfully, her boss called the police (instead of just firing her). The police found her body, and the paramedics were called out in time to resuscitate. (I was called as an emergency contact to the scene). She ended up spending 6 weeks in inpatient psychiatric treatment. Also losing the job. And her kids were relocated to her inlaws, because the courts couldn't allow them to stay in the same home as she was in (and her husband, deployed, wouldn't leave her alone after being recalled on compassionate leave).
10 years later she still thanks God that her kids were in school and that she'd called in sick. Can you even imagine if you suffered a psychotic break around your kids/spouse/at work?
Crazy story, right?
It took a year (apx) to sort things medically & legally.
She's a PHD, works with kids, VERY stable & just all around lovely person. She went back on the lexapro (and lamictle) for another 2 years. The first year to get "even" & meet medico legal requirements for her children to be returned, and then 1 more year to be "safe" before TAPERING off, very slowly.
Antidepressants are AMAZING. But they alter the way the brain functions, and going off of them needs to be handled carefully, or really, really, really bad things can happen.
Its just like driving a car. Cars are amazing, but you HAVE to drive on the right side of the road. Driving on the wrong side has some reeeeallu scary consequences attached.