Anxiety Depression & Stress

I am almost 17 weeks pregnant. I've always had anxiety and used to be on medication but I'm not now. I am so miserable. I have such a stressful job. I cry everyday. My baby is due in September. I was hoping so badly to go on maternity leave in July. According to my doctor I can't go on maternity leave unless there's a medical reason for me to. I didn't have a chance to talk to him about all my stress because he seemed to be in such a hurry. Does anyone know if stress, anxiety and depression due to your job is a medical reason to go on early maternity leave? I can't handle this much longer. I am also not returning to work at all. I'm going to be a stay at home mom. I just have to work through this for insurance reasons.