Egg bound or sick?

I have two chickens and they’ve both been doing well now for two years got them both as chicks. Ever since the season changed, the Plymouth hasn’t made eggs for about four weeks. I thought she was molting first and then she became very lethargic. I thought she was egg bound so I gave her a 30 minute epsom some salt dip. She came out looking much sicker and weaker. It scares me that she might not even be able to stand up on her own. She’s still moving around, but even looks worse now. Should I be expecting the worst?