Thanks for sharing your concern.
I would like to tell you that tongue biting or cheek biting
is called FACTITIAL INJURY
FACTITIAL INJURIES are accidently self enduced injuries. On the basis of habit with a frequent psychogenic background.
It originates as a result of stress
or sometimes without self control. You need to rule out etiology(cause).
like if its due to some sharp tooth then get it grinded.
For relief of present situation you need to get proper clinical examination done.
If cut is too deep then it may require suturing.Otherwise some medicament can be applied in superficial case to prevent infection. For pain relief DOLOGEL can be used.
Its better to consult oral surgeon & get it treated as early as possible.
Meanwhile do betadine
gargles to prevent infection.
Hope this helps