I think i have mouth cancer in the corner of the inside of my mouth?

See below: See your dentist immediately. If problematic, you may be referred to an oral surgeon for a definitive diagnosis. Don't wait.

Cancer of mouth : Cigarette Smoking and tobacco use in other forms increases risk of having mouth cancer . You should consult your family doctor or oral surgeon immediately for examination and further investigation to rule out cancer .

Mouth cancer: Important that you see your Dentist or a specialist Oral Surgeon immediately for an examination. Risk of oral cancer is very low, but increases with smoking (anything), alcohol abuse, age, chronic irritation. Not a DIY problem, you need professional management. Please call a Pro.