stressed out about jobs help?

I have a job at a grocery store working part time for 7.30 a hour , I'm 27 almost 28 weeks pregnant and I'm needing another job. The jobs that in looking at didn't hire me they were at home jobs. My mom and I just got a apartment together and she works at home full time she makes way more money than I do and our rent is $870 a month which she didn't discuss with me. Now she's stressing me out about giving her half the rent which is $400 knowing I don't make that much. My babies father is no longer living so I have no support and I'm so frustrated