There are three levels on which a marriage can operate. At the lowest and most common level, a marriage is doomed to failure. At the middle level, marriages can succeed. At the highest level, marriage can be so much fun you can't imagine life any other way.
The key to understanding these levels is to identify who has the responsibility for making you happy.
Level 1
In a level 1 marriage, both partners assume that it is their spouse's responsibility to make them happy. If that makes perfect sense to you, watch out! Your spouse can't make you happy, and that's not the spouse's job. A wife isn't the maid or the mistress. She didn't marry a guy just for the privilege of doing his laundry. A husband isn't just a handyman. If you or your spouse approach marriage with the idea that your partner is responsible for your happiness in life or the relationship, you may as well call the lawyers now. It will never work.
Level 2
In a level 2 marriage, spouses recognize that he (not his spouse) is responsible for his own happiness. Can you see what burden is lifted from a marriage by partners who see each other as equals who share responsibility for happiness? This simple attitude adjustment allows you to be happy in the marriage independent of your spouse. Your spouse doesn't need to be super human to please because you don't expect your partner to make you happy. You take responsibility for your happiness and your spouse takes responsibility for his.
By combining this with good communication, your marriage has the potential to go the distance. When you need something from your spouse, you are allowed to ask for it. If you remember that she isn't your maid or mistress and approach her as a partner who has the right to accept that responsibility, or not, chances are good she will. If she approaches you the same way, as a partner, the mutual respect will allow you do for her what she needs. This marriage can work.
Level 3
In a level 3 marriage, spouses focus on making each other happy. I know this sounds a lot like a level 1 marriage, but it's exactly the opposite. Rather than thinking your spouse is responsible for your happiness, you need to take responsibility for your partner's well-being, ignoring your spouse's responsibility for you.
Women tend to be better at relationships and, as a result, tend to reciprocate; there is relatively little risk that she won't concern herself more for your happiness than her own if you start with that attitude.
In fact, chances are good that she tried to make level 3 work, and you didn't notice; if she's not there now, you probably didn't. She was probably there in the beginning of your marriage - and perhaps you were, too. If you're lucky, you settled into a comfortable level 2 relationship. You can create a level 3 marriage simply by anticipating your wife's needs. Give some thought to what she really wants and needs. Never spare praise or affection (and don't confuse sex with affection.)
Maintaining a level 3 marriage is easier than you'd think. It takes years to learn, but once both spouses are focusing on each other with no sense of obligation and no expectation the virtuous cycle constantly reinforces the relationship. A level 3 marriage is virtually indestructible because neither spouse would do anything to hurt the other. Ever.