It seems fairly obvious to me that you cannot sleep because you do not take the lorazepam any longer. I am in the same insomnia boat as you. I don't know how long you took the lorazepam for, personally I was on a benzo for years and years. However, talking with hundreds of people on a support site for benzo withdrawal has taught me that it varies from one person to the next on how long you took it for and how long the insomnia lasts. Some take it for a short period of time and have insomnia for a long period of time.

The benzo really changes the chemical structure of your brain and that certainly affects your sleep. I have not slept well or restfully now for almost 2 years either. I wake up feeling like death and have no energy.

It would not hurt to have the sleep apnea thoroughly explored to rule that out. I feel deep sympathy for you and your situation. From what all I have learned, there is really no cure for the insomnia but time. I take melatonin and I think it has started to work better or I am healing.

Not sure if exercise would help you but being really tired does make for a deeper resting period at some point. Best of luck to you!!!