Frustrated & Need Advice

I’m so upset with myself. When I was pregnant early on my OBGYN stated how I was high risk and I gave my job the doctors note for it and they told me that they’re not obligated to accommodate me because I’m pregnant. I expressed so many concerns with my union rep and I told him everything, especially how they started mistreating me as if they well retaliating and he did nothing for me. It was so much stress and they told me that it was better if I resigned because if I got fired and wanted to come back to the company then I wouldn’t be able to so stupidly I resigned because I loved the field I was in but I couldn’t take the stress and I was terrified of losing my baby.. I had everything figured out I had even gotten a place for myself and my child but now here I am with a fresh apartment, car note & no money for anything not even my phone bill so I can’t do delivery jobs like instacart or anything. I wanted to contact a lawyer but would I be able to if I resigned? I need advice badddd (I was working as a mail carrier for the Post Office) & yes I’m currently looking for jobs it’s just not easy and some days I get really discouraged and just ball up. (My advice I wanted was regarding contacting a lawyer NOT places I can work, I’m aware of light duty jobs.. this was in regards to contacting a lawyer )