My chicken is losing balance?

[happy_feets12]

Hello guys,
i will be very happy if someone helps me with my chicken. So she is maybe 1-2 years old, at first she show some weird signs(her one wing was down) and i thought her wing is broken. I wraped her with bandages, but then she stared to losing her balance and i dont know why? I am scared that is maybe Marek?
She wants to eat a lot and drinks as well. I bought her some vitamine B(Thiamine). Its like vitamin B complex. And I gave her this twice a day(today is the third day of giving her this vitamin). Can someone give me some advice what to do with her i dont want her to be put down. In the morning i find her on her back And some picture of her poop. Her coop is always full because she wants to eat alot.

Here are some picture of her and video:

 

[nuthatched]

What's her diet? How much vitamins have you been giving her?

 

[happy_feets12]

What's her diet? How much vitamins have you been giving her?

I give my chicken mix of corn,wheat, barley. I also give them vegetables from our garden(salad,pumpkins...)
This package has capsules with vitamin and i mix it with water and i gave her with siringe in her beak

 

[happy_feets12]

I give my chicken mix of corn,wheat, barley. I also give them vegetables from our garden(salad,pumpkins...)
This package has capsules with vitamin and i mix it with water and i gave her with siringe in her beak

I gave her one capsule per day

 

[nuthatched]

I give my chicken mix of corn,wheat, barley. I also give them vegetables from our garden(salad,pumpkins...)
This package has capsules with vitamin and i mix it with water and i gave her with siringe in her beak

Any real chicken feed? Is chicken feed available where you are? That's is a unhealthy diet that lack vitamins, minerals and protein.
What strength is the vitamins?