In wow if you swap between the frenzy heart and oracles do you loose all of your reputation

The Oracles and Frenzyheart chains in Sholozar Basin are very interesting!

While you're going through them initially, yes, you'll have to switch back and forth so that you lose reputation in one you had gained a lot in, but then you'll get it back later.

Eventually you get a final decision about what faction to go Exalted with and which one will hate you forever.

You can't have both at Exalted at the same time as they are mortal enemies.