Should I stop be Mr. Nice guy?

I found out last month my wife was leaving me. After a few days of surveillance I found out her brother had hooked her up with his next door neighbor. We have been dating since our Jr. year of high school and together over 15 years and married for 9 1/2. She was planning on sneaking out and moving while I was at work. After finding this out I sat her down and said I was sad she was leaving, but not mad. Told her I knew of her leaving , but didn't mention the guy hoping to keep things peace full and possibly resolve things. She has since not moved in with her brother as she stated, but moved in with this guy. Her Family does not care for me much, they never did. They have been pushing her to leave for a while now. The gr is always greener right? I let her take the car, which is better than my own vehicle, all her personal things and she left me with the house, everything in it. I told her we would do the bills for the rest of Nov. since she didn't leave till the 16th and then we would get together and split up everything else. Problem is she has not come over? I never physically or mentally abused her. She just felt like I didn't put her first. Which is fine and she did what she had to do, but why the sneaking around, getting a new man on the side without even considering working things out with me, and now why not come see me to go over the bills and talk about our separation. I was really hoping to do a disalution instead of a divorce as I feelwe can talk things out togethersave on the lawyers and stuff. But they keep telling her it is not a good idea and to not come see me and make me file so I have to pay for the divorce. This has been going on now for 3 weeks and I am ready get something in the works. I have been super nice, letting her come over with most her family and her new mans family to get her stuff, given her her mail, paid for everything since she left. Ieven let her stay on my cell account so she could have a phone as this new man doesn't have a phone, cable, stove, or hardly any furniture. All I asked was for her to come over so we could discuss our seperation alone. I didn't feel her family or anyone needed to be their while we went over the bills, or how we were going to end this marraige. But they say to her it is not a good idea for her to come alone. I really do still love her, and always will. But I have accepted the fact she is gone. Now I don't want to hurt her, but I am tired of being played. I was considering getting stern and giving her an ultimatum, come over or I file. But if I file it is gonna cost her more in the end and I don't wanna hurt her. Just looking for a fresh perspective on the situation and find out if I should stop being Mr.Nice Guy?