Well, my pain is much worse tonight 
so much so that I actually became stuck on the floor and my left leg feels numb
I'm gutted cause I clearly can't run tomorrow (or until I've recovered) I've come so far in 5 weeks and was hoping that I could get through this plan without any major upset but Alas it was not to be
Worse case I'll take the rest of this week off and hopefully continue with week 6 next week.
Oh no!!! What a terrible bit of luck, Clare!! I do hope that your back improves quickly!!
Take the time needed to recover!! The program will be here when you return!! As well as some friendly faces to help motivate and get you moving again!! It is much more important to take care of yourself so that when you return you can run right through the end!!
Get well and keep us updated!!
Get yourself to a doctor. I have had two incidences like this, one particularly bad and we had to call an ambulance to get me off the floor. Good luck, and don't even think about running until it's sorted out.
On a more positive note: after a break you won't find yourself back at the beginning, you do retain fitness, and it will take much less time to get back to where you are now than it took you to get where you are now.
Oh no Clare - so sorry to hear this. Back pain is horrid - no more to be said
Do take time to recover and take it easy when you start again. As smhall says, the program will be here when you return, as well as our friendly faces!
Oh no Clare, what a shame - you were my running buddy from afar, being on the same runs as me!!
Sounds like you need to listen to your body though - and don't get too down, think how far you've come & how easy it will be to pick up again when you are back to being fully fit.
Get well soon
Such sad news Clare... If it is not better in a day or two, a doctor visit may be in order. We are not running a race so the program will be here for you...disappointing, non the less. Sending healing thoughts your way!
Thanks guys, your comments made me much better. Things have improved lots overnight and hopefully I'll be back to running again next week 
You may want to consider seeing a chiropractor. I injured my back (slipped a disk when sneezing) 30 years ago. It came and "went" unpredictably since then and at it's worst I was using a stick to help me walk. I started at a chiropractor (or, as my grandaughter, age 3, calls him, the pirate tractor) about 5 years ago. He diagnosed a slightly twisted spine and extremely tight hamstrings, which were pulling my pelvis out of alignment and making the spine more predisposed to 'go'. He treated the spine with manipulation and I now go for 'maintenance visits' every 3 months or so. He gave me stretching exercises for the hamstrings and I still do them every morning.
And the result? No back 'outage' these last 5 years, no stick, running 5K, running 10K, shovelling a ton of manure (literally, a ton) on my allotment, walking straighter, no pain. Result!! May be worth a thought?
On Week 6 and sudden back pain
Back pain- should I continue?
Bad back = no running week, gutted
Running with lower back pain?
And back to earth...
