If i become seriously ill will the fda allow compassionate use of cytosorb filters to save my life?

Depends: Because Covid affects each individual uniquely, medical treatment decisions are made on a patient by patient basis. If a patient becomes seriously ill/ hospitalized, each therapy undertaken will strive to stabilize that patients condition as it evolves. The FDA has approved of compassionate use of cytosorb filters, but their use is still in a very small number of patients. There is no one cure.