About taking the time for court...you are already involved and doing the right thing is never without cost.
Your decisions to participate affect more than just you and as mentioned, if you do not participate and this bozo kills someone you would rightly be haunted by the question of whether you should have been more active in your case.
As for the additional charges consider this.
Without knowing what the cop meant by "pressing charges" my reply may be way off base. If we are talking charges for crimes of a personal nature such as assault then my answer is off base. If it means just piling on for the sake of piling on then my answer might be appropriate.
The question probably should be "do I want to punish the driver in addition to the punishment he can get from the state?" if you do, then press charges, if you don't then don't.
Just keep this in mind, none of us are immune to the consequences of our actions, but we should also show the same mercy that we ourselves have been offered by our Creator. That said, there is nothing wrong with letting the government mete out the appropriate punishment while forgoing your right to inflict further punishment.
At the same time, however, you should seriously consider a civil suit to recover your medical and other expenses. First talk with your insurance company, especially if they have picked up the tab so far.
This is one of those times where talking with an ambulance chasing lawyer may well be the thing to do. However, don't just settle for any lawyer, or for thier terms. you can negotiate how much of the settlement they get. There is no reason for a lawyer to ever get more than 15%- 20% of the proceeds. Adn be sure that that is all the lawyer gets, no retainer, no miscellaneous fees, just a straight percentage.
If your lawyer says no, find another.
Just food for thought, I'm not an attorney nor do I play one on TV, this is not legal advise merely the rantings of a concerned amateur.