Work rant, thought you fellow twin mamas would understand

I'm sick of my job now. Out of a team of 5 people I'm always in the office and everyone else just comes in almost when they feel like it.

There's meant to be two of us doing the same job, and sharing the workload. I've been doing the job by myself since May as the other person left and the new girl didn't start until August. She's never here as she has a lot of doctor appointments. Even so she has only learned how to complete one task that literally takes 5 minutes, so I'm still left doing all of the work. This girl isn't getting trained and I'm not being told why.

We had one job that I was told I wouldn't have to look after as I do it a lot and they thought I deserved a break. I ended up having to take it over as the amount of stuff that was forgotten and ignored was ridiculous. (One of my managers was working on this job which is why it annoyed me so much).

I don't use my pregnancy to get out of things, quite the opposite. I've had an afternoon off as I was being sick and I've had two mornings to go to appointments. None of the daily tasks get picked up in my absence so I don't have time off because I'd end up picking up all of the work when I come back.

I feel so stressed and I'm getting headaches from it.

The stress is not good for me or my babies but I feel like there's nothing I can do. This girl won't improve overnight but I don't have the energy to train her (my manager is supposed to be) and do all of the work as well.

Sorry for the rant but I really feel backed into a corner here.