Surat Maryam is well known for it's special calming qualities especially for mothers or pregnant women.
For me - I read the seera of the Prophet. To remind oneself of the Messenger's trials and tribulations and his unerring devotion is an inspirational and lifting read whatever your mood.
And also, bare this in mind. Allah swt does not test us beyond what we can endure... so whatever it is, you can deal with it. that in itself is a nice and comforting thought...