Had a quick look at some of the posts in this thread. Benzo's are not for sleep! Your dose will stop working in a few days for this indication and you will have to increase it. They can be used for a few weeks for anxiety (although there is no evidence, besides anecdotal, that they lose efficacy in this indication), and a few months for seizure prevention.
If anyone is dealing with CFS/ME benzo's can be a god send not only because of central effects like anxiolysis, but because of the peripheral benzodiazepine receptor, aka transporter protein (check the wiki on this one) and also aka the mitochondrial benzodiazepine receptor, where it exerts an absurd number of effects for a little known receptor.
I have heard of people like Little Bluestem who have stayed on the same dose for years, but I still urge caution! Kudos to you for not upping your dose in stress and "times of need" lol.
There is a way to use them long term and keep the doses down and avoid tolerance.
What i have done over the years is firstly keep a limit to the dosage to no more then an equivilant of 10mg of valium. Most sleep meds have an equivilant to 5mg per pill ie zopiclone pill is 7.mg = 5mg valium, zolpidem 10mg = 5mg valium etc. Reactions and effects are individual but i alternate nightly between the z-drugs and a traditional benzo, even though they say there is a cross tolerance, i dont believe its 100% cross over as i have found alternating them has helped reduce tolerance.
Theres alot of other non benzo meds which are mostly antihistamines, sedating antidepressants and low dose antipsychotics which all work on similar neurotransmitters to varying degrees. So one could alternate nights using these with benzos or z drugs. Or if one finds the max dose of 10mg is not effective then one could add a small dose of the above antihistamine type meds, but i think at this stage it might be best to take a holiday from benzo's and use the other meds for a few weeks.
Theres also anticonvulsants such as lyrica and neurontin. I will add that alot of these meds and sedating antidepressants are indicated for daily/nightly use and to be tapered off, but i think if they are used as a one off here and there in a rotation with other meds then the typical withdrawal issues arent an issue, but its something that needs to be worked out with your doctor.
So basically one needs a few different meds from a few different drug classes and alternate them in some sort of pattern that works for you that helps you avoid tolerance and keeps doses low. Its extremely rare that one med will work for years on end. There is also a theory that NMDA antagonists can help reverse benzo tolerance, but i dont think many docs would know alot about this so u would have to do alot of your own research on this and again discuss it with your doc.
I think there is a group of us cfsers who will never sleep normally until they find the exact cause of the sleep dysfunction and there is a way to repair it.