Jeremy Meeks first foray into celebrity ain't going so well ... his new manager is already getting death threats ... apparently from gang members.

Meeks' family hooked the convicted felon up with some representation this week -- hoping to capitalize on his new-found fame -- but things quickly went south.

We're told his manager received around 30 harassing phone calls from "gangster-sounding people" ... and one person repeatedly threatened to blow her head off -- saying she deserved to die.

As we previously reported, cops say Jeremy was a member of the Northside Crips gang.

The manager filed a report with the L.A. County Sheriff's Dept.

Still interested ladies?