Hello, I suggest that you change your method of flossing. You are aware of damage done using your current technique. There are many styles of floss and floss holders available. I understand from your question that it must be a difficult area to reach. I recommend you try to relax your jaw and place the floss in gently. Do not stretch open so wide that your cheek is tight against your teeth. There are other soft interdental brushes designed for cleaning between teeth that you can try as well. I strongly suggest you continue to rinse and brush with an extra soft toothbrush. Gently massage the gum tissue. You must be effective but not abusive to your gum and Remove daily plaque. Please keep up with your routine dental exams and ask your dentist to monitor this area. I am glad that you not experiencing any sensitivity in the area, but if you continue to damage the gum area you may risk some bone loss.. A grafting procedure may be required to repair the gum if it becomes damage becomes extensive. Recession of your gum can lead to sensitive teeth and make you more prone to decay. Thank you for your inquiry. I hope you find my suggestions helpful and I encourage you to try different methods. I am sure with practice, you will end up with a satisfactory result.