Don't feel too bad
Tell this to everyone. On Facebook. In the open and sound like you don't really care if people believe you or not, but you know what the truth is.
Thing is, the people who are truly your friends will believe you.
Forget about the rest.
Next time don't give your password to someone...unless you would trust them with your bank account ;)
Also, you may want to report to Facebook that your account was hacked in (although you gave the password yourself and don't know how that would work)
But yes, let everyone know what happened...taking names. and then ignore all the comments
just be like...i wanted to let everyone know the truth and that's about it.