Please help, not able to eat at all 😔

5 weeks and 5 days today and I have completely gone off food! I don't feel sick but I just can't eat.. no matter how hungry I am my body is just turning it's nose up to any food. My taste buds have gone and when I try to eat it's like forcing yourself to eat when you feel really full even though I'm hungry. Please help I don't know What to do. My pre pregnancy weight is low and I'm a bit underweight as it is, scared I'm going to put my pregnancy at risk. Just don't know how to get myself to eat 😢