The best course is to drink lots of water and give the body a chance to flush the chemicals out. By all means stop taking more chemicals and just drink a lot of water over the next few days. It takes 4 - 5 days to get the chemicals out of your body.
The chance of doing liver damage is minimal. There is a larger chance, although it is still quite small, of doing some damage to the kidneys. Flushing with lots of water should reduce the chances of any damage at all.
While you are crapping the stuff out and drinking lots of water be sure to pay attention to your electrolytes. You can induce other issues if your electrolytes get out of balance.
After about 3 days the chemical concentration in your body should be low enough that you can resume breast feeding.