El Toro--
For your question, I would probably recommend speaking to a doctor. If you are taking benzos that much for sleep that you feel it is affecting you, you are probably being perscribed them, so speaking to a doctor is a good idea.
For the other question, I don't think that melatonin will affect how much slow wave sleep you get while on benzos. In fact, most younger people with insomnia don't actually have a problem with melatonin levels (unless they have been taking a lot of excess melatonin that caused downregulation of receptors). Therefore, if melatonin would allow for the return of slow wave sleep on benzos, most young people on benzos would sleep quite well. (In general, melatonin gets decreased with age when the pineal gland gets calcified). However, if you are taking benzos for sleep, you could try getting off of them for a few days and see if melatonin by itself would work. It does decrease sleep onset time. However, if your melatonin levels are fine, supplementing with excess melatonin, (as long as your cycles are reglulated due to light), is bad. You never want to take more than .3mg of melatonin (a dose which you won't find in most stores), as higher doses increase melatonin levels to levels never seen in the brain and cause receptor downregulation--which is bad in the long term.) Too much of a good thing can be quite bad.
If losing long wave sleep is really a cause of concern, you should consider switching to GHB. GHB will both put you to sleep and give you great slow wave sleep. However, doctors won't perscribe it to the usual person with sleeping problems.
