Mayor de Blasio urged troubled city cops to seek help from ThriveNYC amid the NYPD’s suicide epidemic — days after the mental-health initiative spearheaded by his wife bailed on an event for first responders, The Post has learned.

“There is no feeling worse than wanting to help someone and not knowing how,” wrote de Blasio in a department-wide ­e-mail, a copy of which was obtained by The Post, in which he recounts losing his World War II-veteran dad to suicide when the future mayor was 18.

“Yesterday, we lost our eighth NYPD officer to suicide this year,” wrote de Blasio in the Wednesday letter.

But just hours after the mass ­e-mail went out, that tragic number grew to nine as 56-year-old Robert Echeverria, a veteran Strategic Response Group cop, fatally shot himself inside his Queens home.

“I don’t have any easy answers or quick fixes,” wrote de Blasio. “But I want to say: Help is ­always here.”

Among the options the letter specifically advises cops to embrace is first lady Chirlane McCray’s $1 billion Thrive initiative — which just days earlier rescinded its offer to provide counselors for a “mental-health first-aid training” seminar because, according to City Councilman Joe Borelli, pro-cop group Blue Lives Matter was a co-sponsor.

Hizzoner during a press briefing Thursday fiercely denied that Thrive pulled the rug out from under the seminar, accusing Borelli (R-SI) and The Post — which exclusively reported the reversal — of lying.

“It is a disgusting lie,” fumed de Blasio, though without providing any evidence of the assertion.

But a CBS New York reporter then interjected to say she had confirmed that Thrive dropped out of the event due to Blue Lives Matter’s involvement.

De Blasio pivoted to insist that the only issue between Thrive and the event’s organizers was over whether the session was open to the general public or strictly to first responders, and insisted the city stands ready to offer targeted solutions for cops in crisis.

Thrive — panned by critics as a billion-dollar money pit that has produced few tangible results — echoed the sentiment and, despite having backed out of the Staten Island event, said it will hold nine Mental Health First Aid training sessions for each Patrol Borough in the next month.

Meanwhile, the department is searching for its own stopgaps in an effort to keep the grim toll from hitting double digits.

All NYPD employees weresent a voluntary survey Thursday morning asking their opinions on and familiarity with department options for those struggling with mental illness, sources said.

And at least two commands have scheduled “mandatory suicide-awareness training,” department insiders added.

One pushed-to-the-brink cop fighting both personal and professional hardships said that while higher-ups dither, lives are on the line.

“I can barely stay alive right now,” said the source, a 20-year-plus veteran who’s going through a divorce, struggling to find time to see his kids due to scheduling restrictions — and feelings that the department and city he serves don’t have his back.

“The job is making my life ­untenable,” said the source, who’s seeking counseling from his priest. “The department ­executives have no idea what these guys are going through.”

Additional reporting by Rich Calder