I'm going to try to offer some encouragement, and hope that I don't come off souding like a martyr.
I've been a little cranky and a little weepy throughout my pregnancy, which came as a surprise to me since I'm usually neither.
Back in August when I was about 5 1/2 months along we learned that my step dad had a recurrence of his cancer, that it was terminal, and his prognosis was two to three months. I spent a lot of time crying in the car, and sometimes at work with my door closed after talking to my mom on the phone. I traveled across the country twice to visit with him and support my mom before he passed away at the end of September, then went back again for the memorial service. I had to work really hard to pull myself together for my visits, because it wasn't going to do anyone any good if I spent the whole time being emotional. I'd envisioned my late pregnancy as being a relaxing time when I could spend my energy on happy things like buying baby clothes and decorating the nursery, not interrupted with uncomfortable air travel, sadness, and grief.
What I'm trying to say is that though it may be harder than usual, it's still possible to control your emotions in spite of the raging pregnancy hormones. My experience taught me that I needed make the effort to return the kindnesses that my friends, family, and husband showed me, and that I felt much better when I did.
! I hope it makes you feel better that you're definitely not alone!