My car was totaled

First, you need to find out what the car was worth when it was totaled. I don't really believe the Kelly Blue Book numbers on their web site so go to your bank/CU and ask if you can see their copy of the KBB book. Figure it out from there.
Now, one question, was the car payed off when it was totaled or were you still making payments?

Paid off -> take the difference between the KBB value and he insurance check. If the check was less, that's  a loss. If it was more (doubtful, we know how insurance companies work) that's a gain.

Still Making payments -> similar to the above except now we figure it on the amount you have paid off. Subtract the amount you've paid (minus interest) from the check. That's the gain.

Hope this helps. I also hope it was paid off (it's simpler). Good luck.