company is too hung up on the credit score and number of accounts reported, go to another mortgage company that will do "manual underwriting" for the same interest rate and costs. In manual underwriting the creditor will look at your rent and utilities payments to qualify you for the loan so the number of reported loans on the credit bureau won't be an issue.
If you are determined to keep the loan, why not just pay all but approx. 6 full payments. Then pay the regular payment for about 6 months and it will be paid off. This will accomplish your goal of having another established and loan with payments.