feel weak as hell

Sade
I'm 25 weeks and 5 days I drink plenty of water but still feel weak like I'm about to pass out and I already ate... and I been sleeping all damn day but still feel so weak omgg..... I'm actually standing doing my hair right now I had to stop and sit down because I got so weak..... 
Anybody feel week when they drunk plenty of water ate but still feel like your about to pass out ?