Plz send a photo or visit our clinic. The symptoms that you have said doesn't point out towards anything specific.
Though, I can say it might be an infection due to decayed tooth. This can be confirmed after visiting us.
Next Steps
check if the tooth in the side of cheek pain is decayed or not. if you may post a photo here, i can check and tell you if it is visible.
Health Tips
When things are not clear, best thing is to visit a dentist in person and get it clarified.