Am so sorry to hear of your problems.
I fear that you may well have problems with the car’s insurers. Since the car was not driven by the owner, and assured, they will probably, initially try to have nothing to do with it, particularly since it was SORN
And the drunk driver was unlicenced.
But you say “borrowed”, that might make the owner an accessory, and so liable. What do the Police say?
(Probably no point in pursuing a civil case against the driver, since he may well not have the means to pay such a claim, unless he has some form of personal insurance)
Sounds like a legal quagmire, with you could do without, for a whole variety of reasons.
I hope that all will go well for you.
Go at it hard and strong and don’t take” No” for an answer.
Howard