I am always reluctant to use it. As life goes on when my back is in spasm and the kids need taking care of and DH still has to work and I don't like feeling really spaced out. I am also reluctant to ask for it from gp for fear of sounding like i want it rather than need it 
(probably due to my work with people who do that and are addicted and knowing many gps refuse to prescribe).
I have been prescribed it once by emergency gp, was offered it, and another time I asked, and was given 10 2ml tablets.
I normally lay down with my other painkillers and keep very very still to avoid pain, and then slowly start moving after a day (well, every 2 hours or so in the first day, but in pain). But, yesterday I was in so much pain and it was made worse by having a coughing bug, not unwell with it any more just the remnants of the bug, however, each and every cough sent my back into excrutiating spasm which made me cry out with pain.
My GP, when I telephoned and asked for diazepam said no problem immediately, good idea, and gave me a whole box. I guess he knows from my records I dont ask very often.
And they have made such a difference I wish I had not been so reluctant to use it before. I took 4ml at around 2pm, then 4ml at 8pm, and I can stand straighter and walk with much less pain on the third day of my back 'going' than ever before. Amazing. I have taken 2ml this morning as DH is out and I have DS on my own. And I am going to take another 2ml later, and then 4ml before bed. And then none tomorrow.
If this works so well all the time, and I can be up and about within 3 days, and stand a chance of being able to work after 3 days, I might be able to avoid surgery! I can tolerate 3-4 days debilitating condition every 5-6 weeks over surgery, just can't take 2-3 weeks out of action every 5-6 weeks (or less as it has been).
DH is like 'oh dear, she likes valium' 