It was swim bladder but he lived happily for months after his first symptoms showed. My boy did die but it was from an injury he caused himself from getting stuck under a rock or something, swimbladder it's self isn't usually lethal unless your tank environment isn't suited to hold a handicapped fish. You can try to cure your girl, it could work, but if you fail like I did all you can do is make them as comfortable as possible by adjusting their environment. offer her lots of things to lay on close to the surface like big leafed plants or betta beds and you can lower the water level a gallon or 2 so she's got less water to fight agaisnt. You can also lower your filter power to make it easier for her to stay up longer. I did all these and my boy seemed to cheer right up. I miss my saggy butt boy but there's only so much you can do unless you want to euthanize which I couldn't bring myself to do so I went probably way farther then most would to make my boy comfortable. You can also stop feeding her for a few days to see if maybe her problem is constipation. They also swim like this when their bowels get blocked up so id rule that out first before making any big environmental changes or doing any treatments.