Small gum injury, need advice

Hey everyone,
I am probably making a big deal about nothing, but I wanted to post
my issue here on the group before going to the dentist, if need be.

I was brushing my teeth about 5-7 days ago and lost traction of my
toothbrush and ended up cutting a small area on my gum just below my
lower left Canine tooth. The cut is a little less than 1/3 of an inch
and is a white area. It looks like a canker sore, sans the red border.

Is there something I can purchase at a drug store that can help heal
the laceration? Everytime I eat or drink, I get a severe burning
sensation from the injury.

Thanks for any advice on the best method to get this thing healed.

.