Hi Lately Ive Been Feeling This Pinchy Sting Pain On

Hi
Lately ive been feeling this pinchy sting pain on my left cheek. At first i didnt know what it was but i realized my gums were half redor a bergundy colour on the bottom and pink & healthy above by my teeth, a few days in a canker sore appeared and ive been using hydrogen peroxide, but is the redness of the gums normal? Ive also notice my front bottom teeth are a little visible from the root as if my gums were thinning? I havent bled it all just feels sore.