I'm sorry to hear that you're having a troubled time with Maxx! I don't know what could be wrong with her, for nothing seems to have changed in your household...
Is she spayed? If she's an indoor cat and not spayed, maybe she's stressed from the fact that she can't go outside... Well, just wondering

Please stand by here, there lots of people who may give you wise advise (unlike me ) and help you through this.

Nita