As Kaz says, it's a rotten flu dose, and I hope Lissie and Di are feeling a bit better. Do not try to fight it, because it will only make it worse. Just to cheer you up - it was a full week before I could consider spending time out of the bed or chair, another week before I had enough energy to want to go dancing (that's an very reliable measure!) and another week before energy levels could be considered to be back to normal. We were fortunate enough not to get any chest/sinus/throat infections, which would have added to the misery. Our son-in-law has fought and fought, both the virus and all of the above plus a cough (he's a man ) and finally went to the doctor. He was saying yesterday that he had a lot of business in town, and several times had dizzy spells and sweating, and this has all been going on for about three weeks.
We have never had the flu jab but have not had the flu either until this year. You can have the jab and still get a slightly different strain that isn't covered by the vaccine.