Hello
i have gone through your query.Most cases of 
glandular fever are caused by the 
Epstein-Barr virus (EBV).There is no perticular medicine  for glandular fever. Treatment focuses on relieving the symptoms, such as using painkillers to ease pain and reduce fever.
Most symptoms of glandular fever should pass within two to three weeks without treatment. However, 
fatigue can last longer, sometimes up to six months. 
symptoms of glandular fever include:
    fever
    sore throat
    fatigue (extreme 
tiredness)
    a general sense of feeling unwell
    a headache
    chills
    sweats
    loss of appetite
Fatigue is the most persistent symptom and can last for several weeks.if your child experience any sudden, intense lower 
abdominal pain it needs an urgent medical attention.    
feeling of heart beating fast can also be seen in glandular fever.
if the symptom persist then u sud visit a Phyisician.
Hope this ans helps.take care
Regards
Dr. Shesh