Yes, it matters who files for divorce. In your case, its better since he filed for it.
However, i751 becomes more difficult with divorce.
You need to document and keep proof of EVERYTHING that you can to prove it was his doing/ fault. You need as much proof as possible of your "real marriage".
The way USCIS operates is, they view all marriage cases as sham. Its your burden to prove them wrong.
Now the tricky part:
Timing in such cases is crucial.
> Since you haven't filed i751 yet (will do next year), you cant file joint i751 now because that would be a lie (telling govt you guys are together when he has filed for divorce). You will have to do divorce waiver i751.
>> Tricky part with divorce waiver is that you need to have divorce decree in hand to even qualify for it. Though some officers are kind enough to give you 80ish days to get it done.
So its in your best interest either ways to finish up the divorce ASAP. No contest, ASAP. Get divorce in hand before you have to file Waiver i751.
One good thing about Divorce waiver is that you don't have to wait 2 years. You can file for ROC the day you get your divorce decree. But again, I would warn. You would need heavy evidence of real marriage, i.e. Financial + physical life you had together.
If you don't, you will be placed in removal which still isn't the end of the world. As you will have one more shot Infront of the judge.
You need a lawyer to do this. Don't screw this up!