A crazed ex-fireman allegedly launched into a violent rampage after his ex-girlfriend dumped him — and was “ready for war” when he drove eight hours intending to kill her family in New Jersey, according to prosecutors. Brian John Lanzim, 37, was armed with two guns and a bulletproof vest when he headed from Bangor, Maine to South Toms River, after the mother of his two kids broke up with him and filed a temporary restraining order against him, authorities said. He allegedly wanted to kill off his ex’s family to get custody of his kids, according to prosecutors — but his lawyer claimed he was actually trying to die “by suicide by cops,” according to Patch.com . Brian Lanzim allegedly was armed and dangerous when he approached the home. Facebook/Brian Lanzim “He absolutely f–ked up. He f–ked up big time,” Lanzim’s good friend, who asked not to be named, told The Post.…