So, I went to the doctors yesterday to try to find out what has been plaguing me for the last 6 weeks. The evidence points towards a trapped sinus infection that won't let go. I had tried easing down my workouts, giving myself days of rest but nothing was improving. The fact the the infection is trapped and the usual clear out process is not happening makes sense. I have a nasal spray and a course of antibiotics so I am hoping over the next week or so things start to improve,
Luckily for me, even though I have a race in 4 weeks time, I am in the stage of training where I can lay off the intensity and concentrate on improving technique.
Fingers crossed things get back to normal quickly.