Severe headache 11 weeks

Erin
Woke up with a severe headache that is throbbing. Have not had an appetite with this pregnancy. Actually stepped on scale and lost weight 5 lbs in a few days. I'm scared because baby needs nutrients. I make myself eat food even though last thing I want! So not eating much but some. I am assuming my headache is coming from. Or is it something else of concern?