I understand your problem. The problem with suing a tribe is that tribal land is like a different country or jurisdiction and not under the laws of the state in which it is in. State courts may not have jurisdiction and based on the amount of damages, very difficult to find an attorney who will help you to cover your medical expenses and pain and suffering. It may cost you more to litigate than your recovery because of immunity and jurisdiction issues that may apply. If you want to pursue yoru claim, you need to search for an attorney who has experience with tribal issues and successful in in claims against a tribe.