Your chick should be getting game bird starter at 28-30% protein. IF it's not eating that, then boiled egg yolk can be given to help it keep its energy up, but if it's eating proper food, then it doesn't need the egg yolk. Keep the game bird feed available at all times. At this point, considering the lack of growth and size at 10 day, your chick may or may not make it, so you may want to be prepared.
I'm hoping that the temp in the brooder is in celsius, not farenheit!
Please do not give your chick garlic. Garlic is toxic to many kinds of birds, and may be making the situation worse.
If you can, get some more chicks as soon as possible. Quail are social, and being alone is very stressful. In the meantime, you can put a mirror and a small stuffed animal in there to keep it company.