What Causes Persistent And Recurrent Swelling, Burning, And Pain On My Outer Bottom Lip That Temporarily Improves With Hydrogen Peroxide?

on the outside of my bottom lip right below the lip line is swollen, feels like its stinging/burning and painful to the touch and when not touching either. It looks like a sore but its not wanting to heal like a sore. When i soak my lip in hydrogen peroxide its very bubbly but only on the outside area its not bubbling deeper and it calms the swelling a little bit. But after a few minutes it begins to swell up again. and today the indside of my lip has started to swell now too.