What Could Be Causing The Swelling, Stinging, And Pain On My Bottom Lip That Doesn T Heal?

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.