Oh kah, I'm so sorry this is happening I don't know that I have any advice, I've never been in a situation like that. I can say that if I were the donor's wife, I'd initially need a little bit of time to come around to the fact that this was something he was doing, but I certainly wouldn't be stopping it. I mean, you won't "be a mum to him" he will be helping you be a parent with your own DP. And it's not as though she will need to put TTC with him on hold if he helps you out - he can make the donation and still make a baby with his wife, right?

So sorry hun, I hope you can sort something out and start your family soon