So unbelievably tired...

Im 32 weeks and have been told i have low iron. I got iron supplements but my midwife told me to just take 1 a day but i should have been taking 3 a day! It get up at 6am with my kids and by 9am i am so exhausted i cant get off the sofa. Im so so tired, iv never felt so tired, its awful. I get 8 hours a night but its not enough. My hubby is upstairs having a lie in and im struggling to keep my eyes open 😔