Help!! :'(

I am 30 weeks pregnant tomorrow and I'm feeling EXTREME tiredness like ive never felt before in all my life, I'm struggling to even walk about or do anything my body feels ridiculously drained and I don't even do anything all day! My sleeping pattern is a bit all over and sometimes I don't go to sleep until 2am but then I won't wake up till about half 3 in the afternoon yet when I wake up I feel like I could sleep and sleep for the rest of the day! I am on the verge of tears and I'm starting to worry if this is abnormal. Help??