You can, no doubt, negotiate your claim with an insurance company yourself in order to avoid the cost of hiring a personal injury lawyer. But, the insurance companies and their lawyer are very well aware of the fact that you do not know the legal statements about your legal rights and remedies. They, therefore, try to do everything they can to take advantage of you and to effect the lowest possible settlement.
In case you decide to sue, they might even attempt to elicit statements from you that will damage your position.