Clear drainage from nose. allergies & use nasal spray. recent hysterectomy. brain tumor surgery 2+yrs ago.should i panic?

About what?: you don't need to panic, you have reasons for the clear drainage, I don't know where exactly was your brain tumor, but surgery causing CSF leak 2 years later is kind of a remote possibility and it needs to be anatomically related to the nasal passages, if the condition persists check neurosurgery / ENT, treatment anyways is generally conservative

Neurosurgeon: You should be checked out by your neurosurgeon just to make sure it is not a CSF leak from your surgery. Any signs of meningitis should make you go to the ER.