31 weeks and physical work

Im currently 31 weeks. I have a small Chinese delivery restaurant with my husband and sil. We just started so we have to do a lot ourselfs (hard to find good staff). Im working non-stop 6 hour shifts, so no breaks or sitting down because its constantly chaotic and busy. I lift pans and other heavy things and have to run around and bend constantly. I don’t think i will have the opportunity to take maternity leave and i’m so stressed about it... After a day of work i’m in a lot of pain and sometimes can barely walk. I hate complaining and i’m trying to keep strong but its very hard to keep up. Anyone else in a similar position, and how do you cope? What are your plans, and till when will you work?