Marriage is a COMMITMENT
First of all, you're married, so stop looking! To paraphrase from King Solomon, often called the wisest man to ever live, adultery never delivers what it promises. Flee as fast as you can. Marriage is a commitment to stay with your mate until death. Period. If you can't live by those rules now, why do you think you will be able to make your next marriage even better?
The Danger of Love on the Net
Second, Internet relationships can be so very dangerous... You have no idea what is on the other end of the mouse. Life can seem deceivingly fanciful and perfect when you never spend actual time together (in person) doing every day real-world things, like cleaning the house or juggling the bills... Which I guess is besides the point anyway because, again, you're already married.
Of course it is OK to want to be happy -- everyone wants to be happy. But often happiness has more to do with giving than receiving. Besides, you will never EVER truly be fulfilled in your marriage until you have learned the meaning of true commitment and unconditional love. If you are comparing your husband to another man (who by the way will probably come out looking better until you have actually lived with him, persevered through the hard times together, hit that "comfortable" plateau in marriage, etc., etc.), then you will never find the "right one." The very attitude that causes us to go looking, even if it is even within our own hearts, is the very thing that prevents us from ultimately finding what we are looking for.
The "right one" is by definition, the very one to whom you have committed yourself, because that is the key ingredient that allows the relationship to flourish. In a committed relationship, you have the freedom and security to expose the deepest, most personal part of yourself to your mate and to develop the intimacy we all crave.
But marriage takes work - a lot of work. I urge you to put forth effort into your marriage to make it work. Perhaps you need to seek counseling with your husband to work on the problem areas of your marriage or to develop a deeper friendship and romance with your husband over time. (Just because it isn't that way now doesn't mean it will never be!) You should also think about why you married him in the first place. You obviously saw something of value in him -- cultivate those qualities!
P.S. I'd recommend a great book on this topic called "The Heart of Commitment" by Scott Stanley.