I am 25 weeks pregnant and I have no appetite!

As the question says it, im 25 weeeks pregnant and even tho i get hungry i dont feel like eating at all! I know i need to eat for my baby but how do i get my appetite back? I know i shudnt but i have gone like 12 hrs without eating! God i want to eat buh i just dont feel like it! I dont know why! Help me please! I dont wanna be a bad mommy!