Is there any way to get the cross-collaterized credit card loan off of my truck loan with my credit union?

Yes.  The fourth option below (chapter 13) is probably the best bet.

First:     You can pay if off (I know, this isn’t the one you were looking for).

Second:  You can refinance the truck through another lender.  Just remember that if you are behind on payments for that credit card, your current credit union may refuse to release the title unless the loan balance the the truck and the credit card are rolled into the new loan.

Third:  You can file a chapter 7 bankruptcy and surrender both the truck and the credit card.   Just remember that if you try to re-affirm the truck loan with your credit union, they will attach that credit card balance to the loan as well.

Fourth:  You can file a chapter 13 bankruptcy.  In the chapter 13 bankruptcy, you can strip off that cross-collateralized credit card loan from the truck, you can change the interest rate on the truck loan to about 5%, and you can stretch out those car payments over the next 3 – 5 years, even missing the next payment due while we get the case ready to be filed.