Can understand your concern..
As per the symptoms..
Orange paste on your tongue may be due to poor oral hygeine leading to accumulation of food debris on the tongue giving it a orange hue.
You can use a tongue cleaner and clean your tongue twice daily to avoid accumulates over the tongue..
Poor oral hygeine can at times lead to bacterial infection on tongue..
Other reason can be fungal infection
) if you are getting exposed to it.
The best way to cure is to eliminate mold from the environment if it is present followed by anti fungal medication
It may also be due to yeast infection..
Keeping a good oral hygiene
and taking Probiotics in diet like Yoghurt can be helpful homely remedies to treat your problem..
But if it is associated with burning,itching of tongue you should see a doctor soon..
Brittle and cracking toe nails can be due to fungal infection or nutritional deficiency
As you told that you have a yellow hue on the nails and orange hue on the palms and feet it may be due to dysfunction of liver causing increased liver enzymes causing discoloration of the mucosal surfaces and may be diagnostic of Jaundice
You should also get checked for HYPOTHYROIDISM
as in hypothyroidism also brittle nails and yellow to orange hue as well as fatigue and muscle soreness is evident..
You should see a doctor soon and get your investigations done and furthur treatment will be based on the laboratory investigations and clinical examination..
Hope your query is solved..
Thanks and regards..
Dr.Honey Nandwani Arora..