holding on to a fruitless relation is like holding on to a fruitless tree which will not be able to provide you anything for your thirst or hunger.
stepping out of that is most easiest to do and holding on to it by nourishing and owning the tree to begin having leaves and fruits is most difficult.
depends on your patience, stamina, strength and determination.
is it all worth it? you need to have time line defined for any fruitless relation and plan alternative beyond that.