Been running a fever of 105 for a few days and doctors did blood work and so far have found bandemia. What is the worst thing it could be & simplest?

Worst leukemia. Bandemia means large number of immature leukocytes in the blood. Worst answer is leukemia, best answer a simple (tough likely severe) infection.
Fever of 105 degree? This is very high and u may need inpatient treatment. , talk with u physician.