Break Down

Im a full time retail sales manager and bread winner for our househould, a full time mom of 4 girls ranging 16-5, 22 weeks pregnant, and do most of the household chores. I am exhausted. I am failing at work. I just dont know what to do anymore. I am menyally and emotionally exhausted most days, and thats just from work. Anyone else having a hard time holding it all together? Need ideas on how to save my job before I lose it.