Having toungh infections often, is it my sleeping, gastric or other problem? i brush, mouthwash regularly.

Tough to say: Not enough information. Is it a surface infection (yeast/thrush); is it deeper in the tongue muscle; under the tongue? If using a mouthwash, alcohol free is generally better; but it's possible to have a reaction to an ingredient in the mouthwash. Avoid whitening or tartar control mouthwashes/toothpastes. If problem is geographic tongue you may need a prescription mouthwash. See a dentist,

Canker sores: is the most common oral lesions. Most tongue ulcers, infections will clear up by themselves within a week or two. You should see your GP or dentist if the ulcer gets worse or lasts for longer than 2 weeks. Take care.