Extreme tiredness! 😩

Has anyone got any advice on how to grab some energy. Im 8+3 and really struggling, i work at night in a busy restaurant until midnight and feel so tired i could cry. Im home all day with my two year old who is up at dawn and wants constant company and attention. Iv googled tiredness in pregnancy and it just tells me to sleep and have early nights which is obviously impossible in my job. 
Help please!!