OP, I could have been your friend (if it is a abusive relationship).
My new Partner was amazing, he was everything I wanted and arranged, nights out, trips away, I was completely isolated, without realising it.
My friends gave up nearly a year in.
But that was when the cracks started to appear and if I'd have still had support from a friend, I would have found it easier to end it.
I would contact her one last time, in a "do you want a catch up" type of casual way, then leave it.
I think it's harsh to always put it at, "she'll come running back to you when it ends", type of way.
I can't believe that I was in the relationship that I was in, for six years, it's affected my children (lost me my friends) and two years out of it, I'm now going through therapy, for a type of PTSD.
I'm glad that emotional abuse, is now being recognised, in law.