My wife walked out 2

[cbtdad]

There will come a time for a letter one way or the other. Now is now that time. Cnut gave you some give advice. It's not your responsibility to make sure she is being the a good mother. All you can do is be the best father you can be. You can't control or dictate what she does.
You need to do your best to detach right now. The less info you give her the better it will be for you in the whole scheme of your situation.
Look I know its tough. I was your age and son was your sons age when we first separated. I understand how tough it is with the, at that age
hang in there
You are doing great