Dealing with depression while pregnant.

I'm in need of some serious advice. I'm not 21 weeks pregnant with my first and I can't deny the depression being pregnant has put me in. We didn't plan it, though we did discuss having kids in the future when we were ready. I feel horrible. I lash out, I get stuck in these funks. This pregnancy has been all over terrible for me. I can't help the over whelming feeling that I can't do this. That this isn't for me. I'm not even the motherly type. I have panic attacks about it sometimes. But my s/o is so happy about it. I feel like I have to hide it from him because I don't want him to get hurt feeling like I just didn't want a kid with him. I don't even know how  to handle this. It has really gotten in the way of my everyday life. I can't do the things I once had no problem doing. Some days I can't even get out of bed. I tell him I don't feel good so he doesn't suspect anything, but to getting harder to hide. Is there anyone else going through this?! Please, it's gotten so bad.