From the information you have given over here since u haven't mentioned any type of tobacco chewing habbit or areca nut chewing habbit, I'm presuming this has happened due to continuous cheeck bite habbit.....so I suggest you to first of all show to your nearest dentist or dental hospital for further information regarding the lump in your left cheek.

Repeated Cheek bite causing swelling over that tissue, kindly consult oral and maxillofacial surgeon

Hi ! The bump on your left cheek looks like it's from a cheek bite. Please do warm salt water rinses 2–3 times a day, avoid spicy food, and apply Dologel or Mucopain before meals. Chew slowly to prevent further biting. If it doesn't improve in 7–10 days, or gets worse, please visit the clinic. Also, kindly share a clearer picture if possible.

Hi, Difficult to see the bump in the picture shared. Visit a dentist and get a check up done.

From the pic you have provided it seems to look like a check biting issue   . ....since you are a regular tobacco user u need to surely have a dental visit and oral examination done surely

Hello Please consult the oral surgeon for proper diagnosis and treatment