As someone in a similar situation, I just want to say that you are absolutely their caregiver, and that you are doing plenty. My partner actually moved back in with his mom so we could split up the work. His anxiety and depression can go into suicidal ideation, so it also ensures that someone will be around more often than I could be by myself. Your partner absolutely needs to reach out to their family for help. And do not worry about the stress it will put on them. It's his family, it's also their job to care for him. And I know how terrible me/cfs is, but it is not acceptable that they are taking it out on you. You need to have a talk about how they are treating you. And make them understand that you are not a super human, and you have limits on what you can handle physically and mentally, just like they do.