Apologies in advance if this is long, its a bit complicated, but will try and be concise.
After 13ys together, in what has always been a tempestuous and rocky relationship (married 7yrs) we have decided to call it a day and divorce, finally. This WAS a mutual decision, but seems to have changed in his head, to what I want, and is also my fault for 'not trying hard enough' (I really have bloody tried til I am exhausted though, honest)
We are both English, but moved to USA last year, with his job, was meant to be fresh start, but really has not worked that way at all, and has been hell. Not the country at all, I LOVE America, and would rather stay than not. But as we are on his work visas I have no control over this. He has decided the only option is to return to UK, and ASAP. He wants to be back by end of November

I'm managing ok, with a couple of good friends here for support, but I'm really worried about the children. I have 2 girls, aged 9(nearly 10) and 7.
Obviously they know something is up, we have been in separate rooms for weeks now, and there were some pretty loud rows previous to this, which made the final decision for me, I cant have them growing up in this environment.
But what will be the best way to explain, that not only are mummy and daddy not going to be together anymore (when we get back I'm planning to live at least a 40min drive from him) but we are going back to UK? Youngest will be thrilled to be going to UK, as she has struggled to settle here, but she will not be going back to old school/town. Eldest has settled really well, and loves school/teacher/friends etc.
I'm thinking to tell them Friday night or Saturday daytime, and then give them a really nice, reassuring weekend before they go back to school. And to email their teachers, to tell them the situation too.
I feel like the worlds worst mother for doing this to them. And I really need some advice to minimise the damage. Please