This year, I'm fine. Hooray for me.
But
In January 1988 I started a virus that went on and on. I stupidly tried to fight it with exercise (very dangerous, lucky I didn't kill myself) and got one secondary bacterial infection after another - I think I had five courses of antibitoics, and five weeks of sick leave over about three months - the most I ever had to take in my life. Eventually the GP took an armful of blood into those little sectioned-off plastic bottles and sent me for a chest x-ray, after which he told me I didn't have pleurisy, brucellosis, glandular fever, TB, pneumonia, but did have an infection. Gee, thanks doc. He advised me to take a tonic. Which I did.
Over the course of the summer I improved, started fighting sore throats with ice cream as a local analgesic and general unwellness with blue cheese, and boosting my system with protein, but it wasn't until late November that I caught an old fashioned cold in the head and realised all at once that snotty and sneezy as I was, the other infection had GONE! The only time I have ever been grateful to catch a cold, but it saw the other thing off.
So my message would be, don't despair, these things can be clingy and debilitating, look after yourself, and trust that it will eventually shift.