your "cold-like symptoms" and upper airway discomfort are showing a classic expected response pattern. The fact that yesterday's dose of Levocetirizine reduced the severity, leaving only "quite some irritation" today, strongly supports a diagnosis of an acute allergic rhinitis flare-up or a early-stage, self-limiting viral upper respiratory prodrome.
Next Steps
To accurately review the exact pattern of your seasonal airway triggers, check if you require a soothing saline nasal spray to completely clear the remaining irritation, and provide a guided prevention layout, please book a full consultation session via my Practo profile."