Are you aware how high the failure rate of marriages can reach in this day and age? In some places, the divorce rate can even reach a monstrous 87%! In 2009, people do not seem to be as self-sacrificing as they used to be - many just throw their marriage down the drain without much hesitation. As marriages take a lot of constant effort and commitment, maintaining it is certainly not the easy path. I am glad you have made the right decision to not walk in that direction.
With the odds stacked against us, it is quite the task to save a marriage. It has been recommended that marriage counseling can help couples work out their problems; but this only applies when both parties are looking to keep the marriage together. It can be quite difficult when your spouse does not want a role in keeping the relationship intact.
Don't make the mistake of coming up with ways by yourself to save your marriage. This is often fruitless and can even be harmful to what you're trying to accomplish. Don't worry though, I've been in this situation so I can tell you what it's like; as well as what you should or shouldn't do. I know it can be quite devastating watching your relationship go up in smoke. It may even put you in a desperate state where you cry to your spouse and beg them not to split up.
What should you then do? Firstly, try your best to not act desperate. The begging and pleading will only make things worse. I personally went through this, and luckily for me I was still able to save my marriage. What helped me was seeking expert advice from someone trustworthy and unbiased.
It is in your best interest to seek outside advice when you're in this situation as it is the only way of surviving your marriage!