The flu jab hasn’t made you ill, you’ve caught a cold coincidentally. Nor does the flu jab protect you against the common cold, different type of virus.
You have my sympathy though as I too have had a similar cold for the last week. Sore throat, sore ears, headache, bunged up, sinus pain, sore teeth, irritating tickly cough.
I’ve used Lemsip, aspirin, ibuprofen, paracetamol, robitussin for cough, Strepsils, now Sudafed sinus Max (obviously not all at the same time)
And no, I certainly didn’t give it to you!

Better a head cold than chesty one as you’ll be ok to cycle once up to it. I got out yesterday for a coffee meet up and will do the same today. Umm once I crawl out of bed!

Today, lie on sofa in front of TV and drink lots of tea and eat plenty of fruit and veg

get well soon