Sorry for another long-winded reply here, I have strong feelings on the sleep subject
I had that exact same problem. The end of my taper off benzos (meaning, the last 8 months or something ridiculous) was terrible, and the doctor I had been seeing kept throwing stronger drugs at me which a) scared me and b) didn't actually work that well (seroquel and stuff like that).
Ultimately I went way out of my way to find someone who was an MD but also was not enthusiastic about psych drugs, and then when I would panic about not sleeping, I would call him insisting that I needed to just take an Ambien or something, and he would talk me out of it. We did that over and over for
weeks.
Anyway, what I figured out was that all my anxiety about "what if I can't sleep?" was a big part of the problem. One thing the doctor said that stuck with me was that I needed to "trust my body to get the minimum sleep it needed", and he even told me that even if it seemed like I wasn't sleeping at all, if I could lie in the dark and be
calm for long enough, I would get rest.
So, I also had a lot of fear about getting so sleep deprived that I wouldn't be able to work and then I'd lose my job and then I wouldn't be able to pay rent and then and then and then.
What I found out was that it just didn't happen. I was severely sleep deprived for weeks, averaging yes four hours or less for most of that time. It was not any fun, I didn't enjoy any of my free time, and getting through work was hard. But, I did it! My worst fear -- of becoming non-functional or insane, just never happened! And then at some point, it was like a lightbulb going on and I figured out "ah ha! This situation I am in is no fun, but there's nothing
dangerous about it, I don't need to be
afraid of not sleeping, I just need to tolerate it!" And I realized that I was spending a lot of time during the day worried about whether or not I'd sleep, and all that thinking was just, toxic, and was making the problem worse.
At some point my sleep got better. It's still not perfect, and I still have the odd week where I don't sleep well at all for several nights in a row. It's not fun, but it's less of a drag than it used to be -- it doesn't make me particularly anxious, just exhausted. And, it doesn't happen that much -- when it does, it's often a sign that I've been slacking on diet or exercise. It seems like if I eat pretty well and get moderate exercise at least every couple days, that keeps me asleep for 6-9 hours most nights (usually with at least one pee break, but I've had an active bladder since I was tiny).
I will confess that sometimes during weeks where sleep is a challenge I resort to smoking a little more weed than I might otherwise; I don't think this is especially great (or even that useful, since pot messes up your REM cycles), but it freaks me out a lot less than benzos would, based entirely on what I know about my body's reaction to different drugs.