mcol.. just read your sitch.. let me say a few things first:
1. Thank you for your service!! I think about you guys all the time. 2. I'm not active.. I served from 93-99, but you know that adage "Once a Marine, always a Marine"
Your sitch is definitely FUBAR. I can't imagine how you feel being so far away from home and dealing with this.
I'll make a few observations: 1. Definitely can relate to the "being a hazard" while this is going on. I'm a computer geek and nearly got fired. Can't imagine the level of stress you are under. 2. I have to agree that the scenario is 2-3X tougher on the spouse.. no excuse though. She knew what she was getting into. 3. The death of her father is probably reeking havoc on the situation. Didn't glean how much support you were able to offer in that sitch, but if it was minimal (even though you were serving etc) that's a HUGE blow to them. The rock they need to lean on wasn't "emotionally" available. 4. I second that with the "being late all the time" another "emotionally" unavailable statement. BTDT. 5. I agree with Mark.. sounds like she is ready to test the waters with someone else. I got the same "speak" and it all lead to a PA. 6. Definitely agree with not backdating the separation. Be prepared for lots of anger and backlash as you will be keeping her from her "goal".
All of that aside.. this is not your fault. As she says, it takes 2 to make this things work. She has obviously given up without giving you the courtesy of trying to work things out.
Not to insult, but you seem like a very intelligent (officer right?) and insightful person. I would agree with a letter, but in your sitch, it probably would be perceived as more of the same. If you were to try and relate to her, can you do a webcam or phone if possible?
Again.. no begging or pleading.. just reassure her that you appreciate all that she has done while supporting you...
This may not be an acceptable approach now that she is seeking a separation.. it very well could fall on deaf ears.
Probably not much help, but you are doing well by posting on here . Stay safe!!