Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain the white layer over the tongue seems to be due to yeast infection known as
Oral Thrush and the cause can be intake of antibiotics, steroids and birth control pills, dry mouth, diabetes, poor immunity etc..
Red spots at the back of tongue seems to be inflamed circumvallate papillae that contains
taste buds and it is also occurring secondary to infection.
You should consult an Oral Physician and get evaluated and if thrush is confirmed he can advise you to take anti fungals like Nystatin mouthwash,
clotrimazole lozenges and taking ample of probiotics like Yoghurt and garlic..
In case if it does not improve in 2 weeks oral antifungals like
fluconazole ,
itraconazole can be advised..
For red spots you can do warm saline gargles and suck ice pops..
Hope this information helps..
Thanks and regards.
Dr. Honey Nandwani Arora.