I am so sorry to hear about all of your turmoil. Please, feel free to ask questions here. We have a nice little Internet family. :)
You will hear diverse opinions, based on individual involvement in the Church. Some of us here are members, others are former members, and still others are non-members who have either strong family ties or close friends who belong to the Church.
Gaz gave some really great advice:
Gaz wrote:Where you stand and where you're going is far more important than where you've been.
I actually may use this as my new signature, Gaz. :)
Gaz is exactly right. You can't change the past. You can only move forward.
It sounds like you and your wife had some other issues; she knew that your lack of serving a mission was a "sore spot" for you, and used it to "one-up" you in an argument.
Unfortunately, people can hurt those they love more than anyone else. I would encourage you to speak with your wife when things are calm, and gently let her know how much that comment hurt you based on the insecurities you have tried to overcome. I'm sure that she would not respond well to you attacking her on a subject that she feels extremely sensitive about. There are just some lines that shouldn't be crossed, and I think that if you can sit down with her and communicate with her calmly and lovingly, you can both come to agreeable terms.
Good luck! :)
Again, welcome to the board! I am one of the Moderators here, so if you have any questions, please feel free to PM me.