How can I sue Greyhound for losing my package with all my valuables?

When I was moving from NY to LA I shipped most of my belongings with Greyhound. The package never arrived, the estimate is over $10'000 loss. Greyhound offered me $300 which is their package insurance. I denied because I wanted justice. Their service was awful and they kept dragging the search of my package over months. I was in depression for 3 months. I finally flew out to the head quarter in Dallas and looked for my package myself. Unfortunately no luck, just an ocean of other lost bags, without any system. Question is, can I sue them even though they have an insurance or if not can I sue them for emotional distress? Is this something I can do in Small Claims Court? Appreciate your answer! Thank you