Hi. I think you are probably experiencing a weird hormonal thing... it just takes you over during and after pregnancy. I have a son so I've been there... but you should talk to your doctor as a preventive measure, and watch for postpartum depression after the baby comes.

My son is 16 and has a chronic illness, so I am having a hard time with depression myself. Since I am already showing a few signs of menopause, I think I too am suffering from hormonal imbalance of some sort, which can huge mood swings. I think about suicide often but cannot even consider it because my son needs me. This is the power of maternal love, and once that kicks in, you will be happier. My worst days with my son are better than my best days without him. So hang in there and cry if you need to. You aren't alone.