I've been feeling so sad

I've just been feeling really sad. I'm 34 weeks pregnant, and my boyfriend works until 5pm everyday. When he gets home, we don't spend much time together because he's so tired. This week he worked 6 days, he normally doesn't work weekends. We also live with his mom, who is very hard to live with, she abuses medicine and alcohol and privacy doesn't exist around her. I've been trying so hard to over look a lot of things, but today I finally broke down. My boyfriend is tired of me crying, he asked why I was crying but he quickly got irritated. He's never mean to me or anything, he just doesn't know what to do. On top of all this, I don't sleep right anymore. I'm just really sad, I feel like nothing is going to get better. I need some advice and support