Just to piggyback on what some others have said, you need to have a serious talk with your husband where you lay your cards (not your extracurricular interests) on the table. He needs to know that your marriage is emotionally unfulfilling and that you feel stifled by him. If no headway is made, then, and only then, should you start thinking about ending the marriage. Just my opinion, but too many people are willing to yell "no mas" at the first sign of trouble in a marriage without making an honest attempt to troubleshoot the problem.
It should go without saying to not do anything outside the marriage. Don't give him ammunition that he could use against you.