A Nicaraguan diplomat found dead in his blood-soaked Bronx apartment inflicted the heinous wounds himself — attempting to sever his own head after drinking drain cleaner and ripping out tufts of his hair, police sources told The Post yesterday.

Cesar Mercado, 34, a consul in New York — found dead on Sept. 23 — swallowed the bodega-bought fluid, which included sulfuric acid, stabbed himself multiple times and slashed his own throat, the sources said.

A Nicaraguan pathologist concurred with those conclusions, sources said.

The Nicaraguan consulate in Manhattan did not return a call yesterday.