This is a horrible anxiety/boredom habit, like smoking. So many people do it, I unfortunately am the person who notices and it drives me insane. The man who helped me at the Verizon store was gong nuts with it. To stop, just become more aware of when you do it, and maybe try and find a new anxiety habit.For example my mothers friend was trying to stop cursing, so she got this bracelet and every time she cursed she switched wrists, it made her more aware of her actions. The worst time to do it is when people are talking to you, they notice it more, and job interviews are the worst. I really hope you overcome it.
You can also try to use a mouthguard. Not a huge one that will annoy you. But when your mouth starts to heal and becomes smooth it will be much easier for you to resist temptation to chew. I don't know if you're like me but I mostly do it because there is loose skin from previous chewing/healing so I want to bite it off because it's annoying. Hope I helped some =)