I wouldnt file to scare him inti anything. Your emotions are running high because you want a resolution, like everyone says Its a marathon, one of those really really long ones. I just dont think that someone can just snap out of it and return to normal family life in 3 months having done what he did.
Im coming up to 7 months and the only reason i would file if i met someone who i wanted something serious with but im actually not ready for a relationship. I think this is all to fresh for you and him and personally even divorcing wont bring you closure you are seeking.
Continue db, give him space and time to sort himself out. Rachel last thing you need is him coming back not fully committed, integrating himself back into family life and then doing what he has already done to you so many times.
Do you have a timeline for yourself when you are really going to stop trying? A year on? 18 months? What do you feel is reasonable for you? I wouldnt even think now about him coming back and what that would look like at this stage. When he is serious about coming back because he realises he want you and you are his only plan! Not plan B! The. You can tell him that you need time to think.
