Work while pregnant

I have hypermesis and I've been hospitalized twice for it. My roommate doesn't seem to realize how bad it actually is though, she thinks I'm just being lazy. I can barely get out of bed and she says that if Beyoncé can perform at the Grammys while being 8 months pregnant with twins then I can go to work a few times a week. Like, obviously I'm not Beyoncé and this is harder than you think it is. How can I make her understand?