To help with the congestion, itch, and phlegm try soaking a cloth or something similar in hot water and hold it up to you face and breath in and out slowly! Make sure it covers your nose and mouth that way it fixes both issues switching between breathing through your mouth and nose is also most effective. It helps sooth the itch and thins out the phlegm so it won't be a hindrance. It's a temporary fix so you might need to do that a few times through the day but it should help a bit especially right before bed and after you wake up. Gargling salt water will also help.
Feel better and I look forward to the game!