What can I do?

First, you would have the opportunity to continue your health insurance under COBRA so long as your employer had at least 20 employees, though you will have to pay both your (the employee) and the employer's share of the premium (i.e. while you  are allowed to continue health insurance, you have to pay for all it). Here is a link to some U.S. government information about COBRA, including what you can do if you were eligible for (at least 20 employees) and wanted coverage continuation but were not offered it: https://www.dol.gov/general/topic/health-plans/cobra
However, if you are not eligible for or do not elect health insurance continuation, you will have to pay for the doctor out of pocket: we are often so used to using health insurance that we forget that we can pay ourselves. You may be able to sue the person who injured you, if they did so either intentionally or negligently (unreasonably carelessly), to recover medical costs or compensation for your injuries; you may be able to sue the employer instead or in addition, if you can show that the employer was at fault in some way (e.g. unsafe workng conditions). However, lawsuits take time, *and* you need to know what the medical costs are before you can try to recover them (sue for them) from someone; hence, even if you can sue the other employee or your employer, you will have to initially pay for your medical care yourself.