Hi, I am Dr.Prashanth Marka from Hyderabad. I will try my best to help you. First of all quit smoking & remove fear of Cancer from your mind. There is nothing serious, based on your question and photographs the patches can be due to friction between teeth and cheek mucosa. The lumps which you feel under the jaw could be Lymphanodes which are palpable even with slight infection in mouth or throat. It needs thorough examination by a doctor.
Next Steps
It is INFORMATION only, not a substitute for doctor's visit.
Health Tips
Get filling to your decayed tooth which seen on photo