I had shingles on the back of my head and then 2 weeks later, i spent 2 weeks in intensive care with cerebral venous sinus thrombosis. connection?

Hard to say: There may in fact be an underlying causation creating susceptibility to both, and one might consider an immune mediated process or even, something like one of the antiphospholipid antibody syndromes. However, the shingles did not cause the venous thrombosis. Yet, the two items signal some general pathology, and worthwhile to fully evaluate.