A lot of your options may depend highly upon the contract you have signed.
I know little about the contract you are under, it may be worth consulting an attorney to review your contract and see if you have a legal out. If you do not, then you will either have to close on the property or lose your earnest money.
Keep in mind that once under a contract you are liable for the terms of that contract. That is why I suggest an attorney review it. It is possible he will find an easy out for you.
I would consult a real estate attorney. If you want to e-mail me firstname.lastname@example.org
I can recommend an attorney in Kirkland that is very good. An attorney can also answer your
second question of where you advertise to sell your position in this sale. It would be wise
to check and see what comparable units are selling for and to see if your sale is higher
or lower than the comparables.
I tried to transfer the option to buy on a condo in Waikiki from a husband to his wife, and they said it wasn't allowed. We had to find a new buyer to buy with him and we put the title in her name.
Let us know what you find out! I hope you can transfer your option.
You may also be able to come to an agreement to only lose part of your deposit. Be sure you are totally released from your contract and get a guarantee in writing.