Old car insurance

Hiya, I am a 22 year old with autism suffering with my finances. Have loads of things to pay off but I am really struggling at the moment. I am in a situation that I don’t know how to get out of. Long story short I got a car in finance in January and I got insurance one day after I got into an accident that wasn’t my fault. My old insurance paid 6k to the finance company the car was on. Bare in mind they didn’t pay it immediately as they paid the wrong company so took them a few months to sort out. Now they are saying they will only pay 6k not 11k which the car is valued at. Does anyone have any ideas or suggestions? If so please do get back to me. Thank you very much