Brown pigmented regions inside cheeks.

Dear doctor,  I was in the habit of chewing pan masala(without tobacco) for the past 12 years.  I have OSMF and brown discoloration inside my right cheek. I am not able to consume spicy food(even a little hurts a lot). I have quit the habit of chewing pan masala 9 months back and have developed these patches (brown discoloration/ patches) 6 months back. I have quit even smoking now say around 50 days back. I wanted to understand what should be the line of treatment.Will these brown patches ever go away and if they donot go, hope they ll not cause any problems in the future till the time bad habits are discontinued.What can i do so that these changes that have happened in my mucosa can be reversed. Are these fibrosis patches?? Please help guiding me with what has to be done