I choked on juice 3 days ago my throat and back of the roof of mouth burns when i swallow spit or something else is this normal if so how long it last?

It may be: You may have irritated the lining of your throat when you choked on the juice. Like any other abrasion, it may take a week or so to fully heal. The throat is tough as you are constantly eating/drinking and the area may need a little more time. Try soft foods that don't aggravate the area as much for the next few days and let it heal. Best wishes.