I've been blowing my nose so much the bottom of my nose is red and stings.
I've been blowing my nose a lot the last couple days and it's all red and sore underneath my nostrils.
ーI've been blowing my nose so much the bottom of my nose is red and stings.
「鼻をかみすぎて鼻の下が赤くてヒリヒリする」
to blow one's nose で「鼻をかむ」
to sting で「ヒリヒリする」
ーI've been blowing my nose a lot the last couple days and it's all red and sore underneath my nostrils.
「ここ数日鼻をずっと噛んでて、鼻の穴の下が赤くて痛い」
sore で「ヒリヒリする」
underneath で「下部」
nostrils で「鼻の穴」
ご参考まで！
カナダ 
