Except as otherwise provided in Sections 5 and 6 [48-7-19, 48-7-20 NMSA 1978] of this act, the exercise by the lender of its option pursuant to a due-on-sale clause shall be exclusively governed by the terms of the loan contract, and all rights and remedies of the lender and the borrower shall be fixed and governed by the contract.
NMS § 48-7-18