Are my gums damaged from whitening gel? (photos)

I had excess gel (9.5% hyd per) in my tray and it burned my gum between my top 2 front teeth. When I first took the tray off the gum was white I quickly brushed it and think I may have irritated it and now it is dark/red. It has been 36 hrs since it happened. How long will it take to heal and will there be permanent damage? I recently finished Invisalign and wear a retainer full time in case that makes any difference. It is kind of hard to see in the photos and looks worse in real life. Thanks!