You are correct in stating that your wife is trying to escape reality.
Being a wife and mother for some years is rough on many women, especially a woman who feels neglected by her husband - emotionally, physically. This is especially true if she was a woman who relied on her appearance and charm before she was married, before she had children.
Pointing fingers at anyone in the situation will result in deeper problems and, inevitably, more pain for everyone.
I'm so glad to hear that you're pursuing marriage therapy. It would be especially helpful if both you and your wife are in personal therapy, too. Both of you need to know why your wife feels that she needs to escape from the reality of her marriage to you - and how to heal the issues.
Best of luck to you and your family.