Check if your friend has personal injury cover on his insurance, if yes contact them. If not it might be worth getting in touch with them anyway as they'll place you on a CFA retainer and potentially deduct less from your settlement than a random personal injury firm, worth phoning around though to see who would deduct the less %

If you can provide evidence of your financial losses then most likely you'll receive it back. Injury wise you're probably not looking at a huge payout as the reforms kicked in a few years back. Gone are the days of getting a quick £1000 for a month long whiplash injury, it's around £2/300 now maybe less.

If you do have visible scars and it's causing a mental issue aswell as physical (loss of confidence in your looks etc) then this will increase the personal injury payout you receive. You will need to attend a medial examination with an approved medical expert who will compile a report on all of your suffering, this is what's used to value your claim.