Sounds like classic flu, yep. Shit can be tedious, but you can speed recovery up with NAC (2x500mg/d) and Ascorbic Acid (Vitamin C, works as NAC metabolism catalyzer).
I gave my last capsules of NAC to a friend of my father in law (60+ yo) after a two week flu episode, which had a holiday booked nine days later. He fully recovered before packing his suitcase. I only had NAC/AA once, after Covid (Omicron B1) and it helped much with shortbreathedness. Athletes are using it to increase O2 absorption of the lungs before training for events. One can take it for a month safely, but i never read of problems from those who took it longer.