Hello and welcome!
Things are a little slow here today being Memorial Day here in the US. Look for more answers tomorrow.
Benzo dependency is something significant, and should be taken seriously. You cannot stop taking the Ativan abruptly, it can be dangerous (moreso the higher the dose), and as you found out, extremely uncomfortable.
You need to address this with a doctor who can help you with an appropriate and safe taper. Also, you need to do some honest soul searching to determine if you're dealing with a dependency or an addiction.
An addiction would involve a more complex mental component with cravings, abusing the medication, taking more than prescribed, taking it for reasons other than for what it was prescribed. IF you identify, or are suspicious of an addiction problem, then you will need to do more work after tapering off.
Addiction recovery involves aftercare, which can come in the form of NA/AA meetings, addiction counselling, etc. If a person with an addiction doesn't do the aftercare and always keep their guard up, relapse is a strong possibility, as the underlying issues behind the addiction have never been addressed.
Like I said, you have to be the one to determine which you are dealing with. Dependency would just be the body's physical need for the drug...where w/ds result upon the cessation of the drug. If you feel you may have an addiction problem, we have a wonderful substance abuse community that would probably be the more appropriate place to work through this...there are great people over there who have lived it.
http://www.medhelp.org/forums/show/77?camp=msc
Best of luck to you...update us when you can, we're here for you!