Hiya palHi Colin
The guidelines stated will be where you will be sentenced.
I was in a similar position 12 months ago and had quite a bad collision (head on), luckily no serious injuries, blew 69.
I was sentanced to a 18 month ban, like you i was scared of prison and a solicitor put my mind at ease, representing me for just over £300.
Some great advice and examples on this wonderful forum.
After your head on, what did the insurance company do? Are they after recouping any costs they have laid out?