Switching Benzo's?

I took clonazepam for eight years and what I didn't know then I certainly do know now! I experienced withdrawal between doses as over time your brain adapts to the dosage your getting and wants more... I started out at 0.5mg twice a day and ended up taking 3mg by the end. I can openly say now that I have an addiction problem, I took my meds as prescribed but as these drugs are so highly addictive, addiction happens and you kind of don't realize it until you try and come off. I would be hesitant about some addiction clinics as a lot of them (where i live anyway) monitor you while you go cold turkey... its a dangerous idea and the withdrawal is horrifying to say the least. I quit cold turkey (under MY physicians orders) approx 8 months ago, the withdrawal is absolutely awful and I was only able to manage it for so long before I started taking ativan to help. I am now doing it the safe way, an extremely slow slow taper, slowly converting my ativan to diazepam (diazepam has a half life of between 20-100 hours) and then once I have completely switched, I will start my withdrawal from diazepam... to do it safely, this will take anywhere from 6 months to a little over a year. I was given clonazepam originally for some anxiety when I was quite a bit younger but I never took it regularly, kind of as needed as both my parents were really hesitant about drugging me in high school (SMART!)... I spent many years free from all panic attacks and it was my own stupidity that gave in one day to all these pills. It was a terrible decision that I regret more than anything in the world! Trying to come back from it is incredibly hard.
Anyways, to answer your questions, no you will not OD, but if you feel that you are really sleepy and not motivated on clonazepam, you should talk to your physician about lowering your dose or maybe switching to diazepam which has a longer half life over all and is available in smaller doses. 5mg of diazepam = 0.5 ativan approx., I find that is is about 6.5 to 0.5 but that is how my body works I guess, it's not the same for everyone.
And, you should take your dosages at the same time you would have taken your ativan, it is important to keep a steady level in your blood as when this drops, then you can experience break through anxiety and withdrawal.
If you are having breakthrough anxiety on ativan you are probably experiencing withdrawal... breakthrough anxiety is a withdrawal symptom.
Clonazepam will take care of the ativan withdrawal, you won't notice much of a difference switching from one to the other, except obviously for the tiredness etc. But just be careful, I found clonazepam fogged my brain and made it hard to think and do things, it is also incredibly difficult to stop taking along with ativan and diazepam and any other benzodiazepines.
When you are ready to get off totally, google "The Ashton Manual", it is extremely helpful.

You won't feel withdrawal symptoms of Ativan whilst you are taking Clonazepam.

It sounds as though you may have an addiction problem. Have you tried seeking professional help from a drug rehabilitation clinic?