Rejoice Ministries (http://www.rejoiceministries.org/) is the ministry of Bob and Charlyne Steinkamp.
If your marriage is in a crisis, and you are at the point of drawing a line in the sand - you are going to give it your all to prevent divorce - I can't think of a better website or ministry to go to than this one, especially if you are short on energy.
Bob and Charlyne were married when he started having affairs and living out other ungodly behavior. Charlyne went to her pastors and they advised divorce. She did divorce him, but then God convicted her that she did the wrong thing, so she started praying and fasting for him. Eventually they reconciled, he came home, and they now have an international marriage ministry.
Some things to note on this website that are helpful:
Testimonies. When I felt like giving up hope of reconciliation, I would read a few of these and get encouraged.
The daily devotional is great to subscribe to. You get daily encouragement and teaching backed up by Scripture.
If you really are serious about marriage, read and reflect on the Standers Affirmation on the home page. This is something not to be taken lightly, but if it is really what is in your heart, pray it.
There is a place to enter prayer requests and a special place to list your court dates for prayer. Bob's story as a prodigal is on the website. There are various printed materials and radio programs available. Charlyne really does a good job of teaching from Scripture.
This may not be an easy journey, but Jesus has promised to never leave us nor forsake us, and you can find lots of encouragement here to hang on to Him and your marriage.