No out of nowhere, he should have expected it since the last thing he told me before I went NC was to get the "F out of his life," so that's exactly what I did. This was end of September, he reached out to me mid October. At that time I thought maybe we can start talking again, WRONG.... he still told me he didn't ever want to see me to avoid drama and I remember coming to see him anyways to have that last confrontation, he just stood there while I cried. That night something in me just died so I texted him and said I gave up on us and to have a good life, from that day on I had no urge to text or call him, I no longer reached for my phone, I no longer had my phone attached to me all the time either.
Well guess what, the man who arrogantly said to leave him alone texted me on halloween and thanksgiving, I didn't think much of the greeting texts so just politely thanked him. I never initiated any further reply, I never replied in a way that made room for him to reply either. By the beginning of December he started reaching out more and more, random trivial texts and then a phone call that had him saying he thought I called but now realize it's his cousin with the same name. Again, politely answered his questions then hung up.
But right now even though he calls and texts every other day or even everyday at times I don't feel that happy. I'm going to go with what I know right now and not assume that he wants to get back together unless he brings it up and changes. He left me, he left me in despair and grieving. He told me he didn't want me in his life, right now I still can't forgive him. Maybe if he shows me he's sorry and do something, idk anything to prove it then I can let go of my pain but there's no way in hell that he can just pretend nothing happened.
I know you're in a lot of pain but I promise you it'll get better with time. I understand you said your GF is headstrong but that's what I thought of my ex too, but it happened. Just have some faith and don't contact her, what you don't know can't hurt you.