It could be the equivalent of morning sickness. Nit unusual for a female to go off her food for a while.
That being said, I would watch that vomiting issue. If that continues or gets worse. She should be seen by a Vet.
Dies she have a temp? Do you know how to take a rectal temp and do you have a rectal thermometer?
Dies she have any vaginal discharge? If so, what is the amount and color? Make sure there is no odor which could be a sign of infection.
You are saying 7 weeks so I assume you know the date(s) breeding happened.
Our area has been very hot. If it is hot there,try to keep her cool and do encourage her drinking fluids if she is not doing so on her own.
Sorry you haven't gotten any helpful ideas.
Be sure you dog drinks water even if you have to squirt it into her mouth.
Is you dog near birth for puppies? I don't remember how long a dog carries puppies, but it seems you have enough evidence to know she is pregnant.