Aggressive German Blue Ram?

I have a peaceful 20g community tank, including angels, tetra, guppies, a dwarf gourami and a german blue ram, the ram now being the problem, everything I read about them told me they were a community fish and for the first few days that much was true, but now its constantly aggressive to the guppies and angels when they drop down to the bottom of the tank, i think they are supposed to be kept in pairs, and i believe mine is a female, so would a male calm her down and divert her attention? thanks, James