Right, this is difficult. From what you've posted it could be severe depression, but what was she like the first year of the realationship?

Because you say she doesn't leave the house hardly and has no hobbies or friends. She seems to have no sex drive either. Perhaps she could have schizoid personality traits? Also someone else made a good point that she could have been sexually abused a few years ago and it's effected her and she's kept it secret.

Either way you're not happy, so really when it comes down to it you need to put yourself first. If she isn't prepared to change or at least meet halfway, then maybe you should walk away.