I Had The Flu Injection On Thursday 9th April. I

I had the flu injection on Thursday 9th April. I then started with flu like symptoms exactly one week later, on Thursday 16th April. I started taking Codrel day & night tablets for 5 days, when I then realized I should have stopped after 3 day's, so I have not taken any today Tuesday 21st. I have an excruciating headache, & can't stop my nose from running & my eye's watering, & feel like I am back to where I started before I started taking the Codrel tablets. Please help. Many thanks Linda Grima.