Hi, I'd like to help you with your question.
It sounds like you two need to connect again. The stress of your situation has made everything seem hard to your wife and she feels she may be better off by herself. This means she does not feel the marriage is helping her in any way.
Although you cannot prevent your wife from leaving, you can try to convince her to stay. There are ways to show her that you love her and that the troubles you have will pass.
One, be open with how you feel. That is harder for men than it is for women. But if she knows you feel just as upset and want to solve the problems in your marriage, she may find a connection to you.
Two, partner with her to solve the issues. Talk to her, share with her and include her in on your thoughts and ideas.
Three, listen to her. She may feel unheard. Women often do because they need so much more communication than men do. Make eye contact, touch her and respond to what she says.
Four, go out and have fun. Treat her like you did when you first met. Even if your financial situation is difficult, you may still be able to get a coffee and sit somewhere quiet and private. Plan a vacation or special getaway for when your financial situation gets better.
Five, help around the house. If you don't already, pitch in, even if she stays at home and works. People often mistake being at home as easier than working outside the home. But it can be just a stressful, especially with no time limits on the work day and a child with special needs.
Consider a marriage retreat. Sometimes going away and focusing on just the two of you can give a much needed boost to your marriage. Churches often sponsor weekends or you can search on line for ones in your area.
Also, you may want to try counseling again. It is worth talking out how you feel and seeing if you can repair your relationship.
If your wife still wants to leave, ask for a time of separation. This gives her the chance to be apart and see if it really is better for her. Often, people find that getting out of a marriage does not make things easier and can even make them worse. A separation also gives you time to work more on your relationship.
Here are some books that may help you as well:
I Don't Want a Divorce: A 90 Day Guide to Saving Your Marriage by Dr. XXXXX XXXXXe and Dr. William G. Clarke
How to Improve Your Marriage Without Talking About It by Patricia Love and Steven Stosny
Fighting for Your Marriage: A Deluxe Revised Edition of the Classic Best-seller for Enhancing Marriage and Preventing Divorce by Howard J. Markman, Scott M. Stanley and Susan L. Blumberg
You can find these books on Amazon.com or your local library may have them for you.
I hope this has helped you,