Have you considered a (relatively mild) form of dissociative identity disorder? In that case, your imaginary friends would be parts of you. It might be helpful to get some therapy to help you "integrate" the parts and it's too bad that something like that couldn't have happened before you met with your friend from the Phillippines, but that doesn't mean it has to be so disastrous with your husband and step-daughter.

Maybe post something in the Dissociation forum and people there can relate? I had DDNOS but not active imaginary friends as an adult.