I found NC to be useful because me ex was manipulative. I needed that headspace to work out what was really going on. I was far too wrapped up in what he was saying and he had a knack of twisting things so much that I didn't know whether I was coming or going.
I would always suggest NC in situations of manipulation and/or abuse because having a rest from the BS (or more serious abuse) helps get on an even keel. It is also invaluable in seeing what the ex does, rather than being swayed by what they say.
Exactly my situation. The professionals I worked with who met with my X during our separation and NC period all came back saying "in this situation, if you don't keep the NC, you will be back with him. That is how convincing he is, even to us, who are on your side and who are not emotionally involved with him."
NC gave me the gift of space, which made it possible for me to realize and feel that I was relieved, un-anxious, and
happy when he was removed from my life. I still felt (for a long time) that I was
wrong in leaving and going NC and that I had failed him and was responsible for him and his feelings... which is exactly what he wanted me to feel, and exactly what he expressed every time he broke NC. But the longer I spent not talking to him, the more I realized what a bunch of horsefeathers that all was, and that really, it's not that he loves me and can't live without me, it's just that he's really, really pi... upset that
his furniture got a mind of its own and did something he couldn't control.