In reply to cat88: Well in many ways you are a lot better off than I was a few years ago when knocked off my bike by a BMW reversing out of a carpark onto the main road. In the time I was pursuing him he had managed to change his job, his car, his insurance company and his address. You at least have an identifiable and insured person to go after, also some witnesses (get their names and contact details if at all possible, if you do contact them be as polite and matter-of-fact as possible).
The main requirement is persistence, you will need a lot of it and also a lot of time. You need to document, with as much supporting evidence as possible, what it has cost you both in terms of actual damage, injury and loss of earnings and other costs, with dates and quotes. Get statements from employers and doctors if you can, so you have objective support rather than your own opinions. With the police, you will need to be determined and polite, but do not let them drop things, sideline them or avoid action. If possible, get the name of the officer concerned and harass him/her in a reasonable but unrelenting manner.
Do not be emotional about it, it has now become an administrative/bureaucratic matter and your opponents will play games, so should you. Justice doesn't enter into it, you are out for the best result you can realistically get. Don't lie, but you do not need to be excessively scrupulous about telling the whole truth.
In the meantime, enjoy the process. Some of the excuses can be quite hilarious in a morbid way, as for example from my culprit :
Him :"Well Mr X, I think I was mostly to blame, but I think you were partly to blame as well"
Me : "How would that be, I was cycling along the road well light and clearly visible, obviously with right of way and you reversed blindly out of a carpark into my path and knocked me across the road?"
Him : "Well I think you were cycling pretty fast and not as careful as you might have been"
Me : "Mr X, I very much doubt if I was exceeding the speed limit and it is hard to see how any amount of prudence could stop some idiot reversing into the main road from an dark corner and knocking me across the road"
The policeman, when I finally nagged him into contacting the culprit, calling him on his mobile : "Hi, can I speak to Alex please"
Alex : "Hi Alex calling, what can I do for you?"
PC : "This is PC nnn from Police Station xxx, investigating a road accident involving injury for which it is alleged you were responsible and have failed to supply insurance details"
Alex : "Sorry, Alex isn't here now, we don't know where he is or when he will be back"
And many more equally funny exchanges, or they would have been funny if they had involved someone else. Eventually after his insurance company was stalling as much as he was, I had to get an ambulance chasing lawyer involved. It then became too much hassle for his insurance company (I did eventually find out who they were), so they settled for at least 3 times the amount I would have initially accepted.
Good luck. The process is neither easy nor quick, but stick to it if you are sure of your case and you should get a reasonable result.