I think my dogs Stomach has turned...?

We recently adopted a German Shepherd and he is 11 months old, he loves water (drinking it) and always gets excited when we get his food ready. He loves to play fetch etc, but now he won't do any of the above... Play, Eat, Drink. Unfortunately we lost a main source of income and cannot afford to take him to a vet... I love him to death and id do anything for him, he moans a lot when he just lays there, is there ANYTHING I can do for home treatment?