I am a 36 year old man from Arkansas. I have been married to my wife for 12 yrs and we have 2 children 10 & 12. She told me Saturday she wanted a divorce because we have argued for many years and she has had enough. We seperared 2 yrs ago went to counseling and were able to reconcile but I was the only one that changed but she said I didn't change enough . She also told me that the reason she didn't change was because she didn't need to I did. Please help me understand what happened to us . I love her so much but she has already gotten a lawyer . What do I do

Start planning for your new life apart.

You need to set up some clear stabilty in this situation for your kids, they will not understand properly what's going on. Costs are going to be a factor, so sit down with your wife and start working on budgets and how you will afford a dual-residence lifestyle for your kids and your finances.

It's hard to say what happened from your short paragraph, but the thing that grabs my attention is when you said "the reason she didnt change was because she didnt need to i did". It takes effort on both parts to make a marriage work, no good one of you changing while the other stands there with their arms folded definantly demanding more change from their spouse, and unwilling to do so themselves.

For now, call her on it. Just agree and say something like 'yeah okay, no worries whatever you want' and don't chase after her. Give her some time to reflect and let her see what life will really be like without you, if that doesn't make her think twice, nothing will.

There is a push-pull effect happening here, i.e. the more you resist the divorce and chase her, she will become more determined to proceed with the divorce. I reckon the best thing to do now is give her some space, let things cool down a bit, and hopefully she will listen to the voice of reason in the meantime.

Change.

Where ypur arguments ever violent, don't mean to be invasive, just trying to get an understanding.

I agree with roogirl. The ball is in your wife's court, hold back and watch how she hands your acceptance of her request for a divorce.
In the mean time, try move on and enjoy your life, this would really piss her off and might wake her up, because you always want what is not yours (anymore)!

Be there for your children, stay in contact with them, they are probably confused and hurt by all of this, they need to know you love them, but you know this. Good luck.

We never had any sort of violence in our marriage. But we argued a lot of the time. I am trying to stay away from her but I can't seem to keep from calling or texting her . After 15 yrs it is just unnatural not to communicate with her. I guess I need to just suck it up and try harder

It would appear she did not take counseling as seroius as you did to want to try and make changes to make a relastionship work ( depending on all of the issues of course.
At this point, she has an attorney, so what do you do, hire an attorney and try to get custody or visitation according to terms that you want and those good for the kids.