No. Any belief unfounded by good evidence is irrational, and when it persists in the face of contradictory evidence it becomes delusional. Delusions don't usually involve the inability to perceive physical reality, or false sensory input or analysis, ie: hallucination.a false belief or judgment about external reality, held despite incontrovertible evidence to the contrary, occurring especially in mental conditions.
"he began to experience hallucinations, delusions, anxiety, and agitation along with dizziness and nausea"
I would say delusion qualifies as a psychosis, according to the definition.