depression affecting my marriage

I've been having a really hard time with my depression especially after having my daughter. I haven't been able to motivate myself as well as I used to and I can't even get out of bed most mornings anymore. Now I'm pregnant with our 2nd and my physical health is now effecting me. My husband works at night and does what he can to help me. When he gets off in the morning he'll stay up through most of the afternoon so i can get some extra sleep since I've been having a hard time falling asleep at night. But I feel like such a disappointment, he gets so frustrated sometimes because he feels like he's taking on everything and I don't blame him. And at times we'll get into arguments over stupid things and it feels like we're starting to hate each other or like we're just putting up with the other. I don't know what to do, I feel like we should talk to someone, i know i need to but I don't think we could afford it. Im at a loss here and I'm angry and upset all at once and I feel like I can't do anything to fix it.