Work VS baby

So I am 30+5 and have had a recently simple pregnancy so far. No complications. I do work a high intensity job at a hospital. I am constantly bending down, lifting, and pulling patients. Never had an issue until recently. On our unit we have about 12 patients. Doesn't seem like much when I say it but 3 of those are recently amputeed patients which means you do most of the heavy lifting and they're all men that weigh over 150. We have 1 combative dementia patient that got a knee replacement and the rest are hip replacement or non surgical hip injuries. These people are in pain, can barely walk and are in here for 3 hours of therapy daily to get back on their feet again. Or foot. Anyways moving on, the job is hard enough as is because we have to get them up out of bed 3x daily for meals, when they have more than 30 mins before therapy they like to get in bed and we can't deny them, so I am putting them in and out of bed multiple times daily. Lifting their feet to get them in bed, doing most of the work since they're compromised. So I'm basically working all 12 hours walking up and down the unit to help them all and I barely get to sit and rest for myself. Lately it's been an issue because we are short staffed and my blood sugar has been drooping every shift because I don't have 5 mins to eat something small from 6 am -1 pm which is my lunch. I am constantly busy until then. Well today I find out I am scheduled by myself. Yes, the nurses can help, but they don't is the problem. So I depend on the other aide to help me. But today it's just me. We have safe harbor which is a number you can call to report if your work assignment is dangerous or you can't take it on for some reason. I am highly upset with my job and them not caring that I am in my 3rd trimester, not to mention I work 4 12 hour shifts in a row. I don't know what to do. I feel overwhelmed with my assignment and I couldn't sleep well last night because I worried about it. I worried about going in and telling them like it is and standing up for myself and getting fired.

It's not fair to me or my patients for me to be alone. I need this job. I need my PTO for maternity leave in May and I need the health insurance but at what cost? Breaking my back and not even to be appreciated or worth calling someone in to help me? What do I do in this situation ladies?