Pay off the credit card. Then take the other $7,000 and apply it to the principle of the truck. Then take the $600 you were paying towards the credit card each month, and apply it to the principle of the truck each month (in addition to the regular monthly truck payment). You will no longer be upside down on the truck in pretty short order.

And don't ever put yourself in a situation where you will be upside down on a vehicle again.