If you are truly ready to file which I think you are BSing yourself I would say something like this:

W we have been sleeping in separate beds now for almost a year. I understand this has been very difficult for you but I can no longer live my life in limbo anymore. I love you and I adore you and I would really like for us to get into counseling and work this out. Listen carefully to her response and validate when necessary. If she agrees to counseling excellent! If not you file.

You have to be congruent with your words. No lighthouse BS I will be waiting as plan B.

I just want to warn you ahead of time 10 times out of ten you are not going to get the answer you are looking for.

Good luck!