You may be having Glossitis, or inflammation of the tongue. It could result from various causes, such as infection (bacterial or viral), injuries, allergic reactions to foods, drugs, etc. and some systemic diseases like vitamin deficiency. Some precautions that you can try at home are: maintain good oral hygeine,rinse your mouth after every meal, use an antiseptic mouth wash like hexidine, avoid any new toothpaste, avoid sucking sweets, chewing gums, etc, avoid smoking and alcohol. If the symptoms persist or there is severe pain, any swelling of the tongue or bleeding, then you should approach your doctor.
You may try this link for more information: http://www.umm.edu/ency/article/001053.htm