Tongue red inflamed. There. plz advice!

There are few reasons for this - 1. Iron / Vitamin deficiencies - get a blood investigation called CBC done and get a consultation from a physician with these reports. Start eating fruits, vegetables and green leafy vegetables and nutritious food. Also clean your tongue after brushing with a tongue cleaner or with the same tooth brush when the the toothpaste foam is still in the mouth. Keeping the tongue clean also will reduce burning to some extent or fully sometimes. 2. Probably geographic tongue - check if the red areas on the tongue are seen in the same place always or it keeps shifting to different areas of the tongue. If it keeps shifting,  it is called geographic tongue and this is a harmless condition and nothing to worry.  In this situation also it is good to clean your tongue immediately after daily brushing.

get the blood investigations CBC done and visit a physician. Avoid highly spicy food and very hot stuff. 

eat nutritious food,  drink milk daily which also has many vitamins and  keep your teeth and tongue clean