Depression, Night shift and Pregnancy

Hello Fellow Nurses...
I have been in my position for 6 months. I just found out that I am pregnant and just started nights on my unit. I have never had depression before - but I am in it bad. I can't get out of bed, I am always crying and have lost my appetite. Although normally I would be happy to have my clothes fit a bit looser - this is not the time.
I spoke with one of my bosses and told her my situation and how I am feeling. She was very kind, but isn't going to have any positions on days for 6 months to 2 1/2 years... Everyone says that the first while on nights is the hardest and I am trying to get through... but this is the 3rd week and I feel the same way.
I asked about going part time and she said that there is a chance that will work... she's checking into it. I will lose a lot of money that I need - but my mental health is worth it. (I will still have benefits, but will pay more for them and loose my sign-on bonus and I am living paycheck to paycheck as it is.)
I would really like any advice I can get - I hate feeling this way. I am suffering and my wonderful 4 year old is as well. He is my saving grace at this point. Luckily, my family is very supportive and is helping out with the 4 year old.