I agree with tambo. Go to a solicitor you know and ask if they'll do this, don't take any notice of adverts or firms who ring you up. Whatever you do, don't pay any fees up front - solicitors' fees are paid by the party found liable.
You need to get this documented a.s.a.p. so write it all down, make a folder with all your pictures and measurements, hospital details etc - it's very easy to forget details only a few days later. KEEP A COPY. When I used to deal with insurance claims, we were always told that the person who keeps an accurate immediate record of everything puts in a far clearer case that someone who's asked to recall details, weeks or even months later.