So I'm having a lot of back pain/trouble and my current job is very physically demanding. They have…

So I'm having a lot of back pain/trouble and my current job is very physically demanding. They have allowed me to work more reception and I have a maternity belt I am wearing all day. I talked to the manager about going part time and just working mornings, but she'd rather have me work in the afternoons which happens to be the most painful part of the day for me. So she asked if I just need to stop working altogether. I can't afford to stop working. Anyone have any advice or have gone through a similar situation themselves? Thanks.