I'm not a lawyer, so this isn't legal advice. But here's what you do:
Create an Illinois-style land trust. Call it the "Lori [your last name] Land Trust." (The name doesn't matter at all; you could name it anything you want.) Transfer the ownership of your property into your trust. You're the beneficiary of the trust.
Note: Transferring your property into your land trust does not violate Countrywide's due on sale clause. See http://assembler.law.cornell.edu/uscode/12/1701j-3.text.html
-- TITLE 12, CHAPTER 13, Â§ 1701jâ€“3. Preemption of due-on-sale prohibitions. Paragraph 8 exempts: "a transfer into an inter vivos trust in which the borrower is and remains a beneficiary and which does not relate to a transfer of rights of occupancy in the property;"
Now, market the house for whatever market value is. However, what you will be selling is not the house itself, but a beneficial interest in the trust. You then execute a possessory agreement (similar to a lease) with the new purchases. They agree to lease the property from the trust for, let's say, 2 years, or however long you need to go with the mortgage to get out of the presale agreement. The amount of their lease is equal to, or greater than, your cost of principle, interest, taxes, insurance, and any condo or HOA fee. In short, they're paying an amount equal to or greater than your commitment to Countrywide, plus any condo or HOA fees. That money is paid by the resident beneficiaries (the purchasers) to the trustee (the owner), who then appropriately pays Countrywide and your homeowner's association.
The beneficiary agreement provides that after x years (your choice), the property will be brought out of the trust and sold for full fair market value. As a practical matter, though, because the "buyers" (the resident beneficiaries) are also beneficiaries of the land trust, any rise in value will be offset by their ownership rights in the trust. So when the property is brought out of the trust, they refinance the property and the deed is transferred to them. You receive the proceeds--the profits, if any.
I've put a link below with more information. However, it is somewhat complicated. Contact me for more information, if you want. But, to summarize, using this technique will allow you to sell your home with no out of pocket cost to you, other than the cost of setting up the land trust.
Hope that helps.