<s>[INST] I have a canker sore on the back of my jaw but at a place where the jaw is connected to a inside of cheek. Whenever I close my mouth that part of skin is squeezed/contracted ( and thus my canker sore) .. I get canker sores frequently .. Its creating problems in eating and speaking...the canker sore is on soft part of skin behind the molar that connects to the inside of cheek and Im sure its not my wisdom teeth...Ive been under a lot of study related stress lately and m not getting proper sleep due to my studies... Im 18 yrs old... Any help wud be appreciated [/INST] Hello, welcome to Chat Doctor. It is common to have disturbed sleep during stress of study. Sleep problem decreases concentration, which further exacerbate stress related to study. Following steps will help you:-Make structured routine and give proper time for study.-Minimize caffeine intake (tea, coffee and cold Chat Doctor. For canker sores, meet nearby dentist for evaluation to rule out or treat dental problem. Wish you good health and all the best. </s>