not necessarily but something big has to change so you can both be happy in the relationship. Like others have suggested, possibly a housekeeper, dog walker, professional caretaker, etc. but all of that relies on money so it may also become a financial burden as well

Some people just aren't equipped physically or emotionally to take on the role of a care taker. Have a serious talk with her about what you're able to do and what you aren't. Have her talk about what she expects from you and if she can keep up with this arrangement for an undetermined amount of time. You can try and mitigate things but she may not be up for this kind of lifestyle which sucks but as it sounds now, everyone is miserable.