Seeing something noticeable other then normal in your body is a sign of attention to be taken.  In your case, as you are saying hairy tongue appearance, is a condition not to be ignored. Without looking into your current situation diagnosis and treatment options can't be decided. It's better you consult with a dentist as soon as possible.

Coated tongue may be due to fungal infection. Topical and systemic antifungal medication has to be taken to cure  this.you can consult through this for prescription of medication and instructions on investigations.

The hairy appearance of tongue is because of papillae. If it was not like that before and is appearing like that now then you need to consult a dentist. For the coating use a tongue cleaner everday to maintain hygeine of your tongue if the coating of the is also not getting scraped off then again you need to visit a dentist. The white line is called linea alba and its normal if that is causing burning sensation or any problem then it might be concerning.