Okay so I've been experiencing unpleasant tastes in the morning which can lead up until the afternoon I thought it was my retainers because they often taste unpleasant when you have had them in for a night, then the other day I noticed that at the back of my tongue I have got white scaly skin with 3-4 red circle spots its right at the back of my tongue it does not hurt at all but I'm quiet worried of what it is?

Depends on your oral hygiene. Constant care of teeth, gums and tongue are necessary when wearing any type of appliance in your mouth over night or during day. Can't diagnose what could be wrong with your tongue, impossible to do on the Internet, but appears to be something unpleasant you should ask a professional about.