Ok, my local doctor has carried out a full examination and gave me the all clear, but I still feel under the weather.

Are there any web services that help to diagnose?

yeah webmd.com is a good one also yourdignois.com(sp sry) are good and very detailed will ask u so many questions that ull probably get a better answer then ur doctor told u.. @ least in my case i havent gotten an answer to what i have in a year so occassionally with new things i refer to them and it keeps me to date!good luck and feel better