I was sucking on a glass a month ago. The bruise is still here. When will it heal?

I had a purple circle-shaped bruise around my mouth for awhile after I was trying to create a vacuum by sucking a glass to my mouth. I did it pretty bad and it was dark purple almost blue and I thought it had healed for awhile but its almost as if its back again, or possibly I just got used to it and now I’m realizing it again. I’ve had it for the past 2 weeks and its not getting any worse but its not getting any better. Does anyone know how long it takes this thing to heal? or will it heal?
Thanks in advance for any help, Bob