I would completely stop the antibiotics and the wormer (never give both at once either). That can cause loose poop and wreak havoc on their digestive system. You're probably inundating her with too much medication right now, though I certainly understand the urge to do something. Overmedicating a chicken can do more harm than not medicating at all. For example, I never use antibiotics unless I am 99% sure there is an infection that they may reach and that is almost never. If these hens are having serious reproductive issues, no medication will help them. That is the harsh reality of it. There is no cure for these issues. Internal laying is terminal so nothing you give them will have any effect, if that is what is happening. It will cause loose poop and weight loss, but nothing you give them will cure them and may exacerbate the loose poop issue. Best to do is give caring supportive care-good food, clean water and a warm place to bed down in cold weather. And let nature take its course. This will be a learning experience you can carry into your chicken-keeping future. I know it isn't easy to watch. Many simply choose to euthanize the hen instead of letting it continue. I don't unless she becomes non-responsive.