Me & my husband planned to build a house with a certain builder here in AZ. It was only a land that we agreed upon it will take months. To nearly a year to build a house. We paid earnest money aware that if we change our minds about the house, we won't have our earnest money back. Something happened along the way which led us to change our minds in buying the said house the builder started building; put the cancellation into writing as the builder required; this time they are suing us for not buying the house when they already had our earnest money. . Help!. we don't know the real estate law re; this. Thanks in advance!

A lot will depend on the contract but yes they can sue you for all their loses.

Once you commit to a contract and they start building you can't just "change" your mind without paying him all the money he would lose. This can be much more than the earnest money.

You need to get to a real estate attorney first thing in the morning and start working this out.