Before I begin, let me say I am currently in the process of being diagnosed with CFS so I am not sure how much help I will be with regards to your questions but i will try! I have been unwell for just over a year and up until now doctors are only now getting to the root of the problem, suspected CFS.
Unfortunatly there is no specific test which can be done to diagnose CFS. I have been told by my GP that it is a case of using an elimination process. All other areas need to be looked into before Doctors can pin-point your particular symptoms on CFS and this can take a very long time!! Usually alot of blood tests are carried out to rule out all other possibilities such as liver function, kidney function, blood count etc. You may be required to have scans, X-rays also if there is certain areas your Doctor would like to look into. It is not a diagnosis they rush into dishing out to patients without checking all other areas first. Most patients have a variety of symptoms along with the chronic fatigue such as muscle pain and weakness, hot sweats, dizziness, pins and needles, balance problems, brain fog, sore throat, headaches etc... Doctors are unable to diagnose patients with CFS for just being tired. My Gp has told me that the patient has to have been Chronically Fatigued or have a mixture of other symptoms for at least six months before they will consider investigating into CFS. It is thought that Virus' can be the trigger of CFS. In my particular case I had severe Glandular Fever which never got better but worse!
My throat was and still is affected I have ulcerated tonsils and am taking antibiotics to try and help. How exactly was your throat affected by the virus?
It is possible that you could be suffering from CFS.
How long have you been feeling the way that you are?
Was your throat infection / Virus recent?
What tests if any has your GP requested?
Virus' can take a very long time to fully dissapear, sometimes up to a year or more! so it could be possible you are still not fully recovered from that.
If you feel you need further investigation you should go back to your Doctor and let them do tests. It's better to get these things sorted sooner rather than later!
I hope this post has been of some help, keep in touch.