so in one one of the books(to lazy to check) jacob said something about not getting older untill the give up the wearwofl thing so can jacob live for ever?( idk maybe i read the passage wrong)

Well i am not sure about forever, but he can definatley live for a long time. Like in the Quileute legend about the third wife, they mention that someone [i dont remember the name now] lived the lifetime of three life's... so yeah i am not sure about forever though. Its possible though, cause the process of getting older stops when he is in his wolf form. And he is a shape shifter.

If I remember well, the story of the third wife is in the Eclipse, I too don't think they can live forever, they just age much slower, and they can be in that certain age as long as their tribe needs their protection...

A werewolf can live forever as long as he or she keeps shifting into the wolf form. Normally, the wolf will choose to begin ageing again once his or her imprint is at the same age, unless he or she has imprinted on an immortal.