Hello,Based on the photos and your 5-year history of chewing tobacco, these lumps need a physical clinical examination to rule out any serious conditions. It could be a simple cheek bite or irritation, but we cannot ignore it due to your tobacco habit.
Next Steps
Please visit a Dentist or an Oral Surgeon immediately for a biopsy or a clinical check-up. STOP chewing tobacco completely to prevent further irritation of the tissue.