John i hope you get it sorted soon. My hubby had a chest infection this year and it took ages to go. he ended up with good old Prednisolone and antibiotics ,which sorted him out.
The only marathon I did was about 48 hours preparing the Capri for its first competition which was Sunday, bearing in mind I got back home to the UK the Thursday afternoon before!
Drove the car to Santa Pod in the wet and rain to spend another marathon session cleaning all the road muck just to get the cover on to keep the rain and dirt off until after the car was judged.
Go on holiday for 8 days come back cream crackerd and then no sleep for three nights get car ready for competition and pass out Sunday evening to be at work for 7:30am.