Most likely you have a virus that is suppressing your bone marrow some. This can explain the fevers and the subsequent increase in the WBC count.
The more concerning thing would be a leukemia or lymphoma that can cause all your symptoms as well. It's less likely but must be considered.
Follow up with your doctor is essential. You may need to see a hematology/oncology doctor if your counts don't improve.
Advice and opinions given are based on the information provided and must not be considered an official medical recommendation. The limitations of the internet prevent an appropriate evaluation. Always consult your doctor if there is concern.