Life is about grabbing and missing opportunities we come across. We accept this sooner or later, under the name of destiny. You missed the opportunity to express your love because of your introvert nature, now accept it as your destiny. This is the healthiest way you can console yourself. Comparing your wife with her will only ruin your present and future life. You should also remember that you are comparing two different people in two different situations and roles. There has to be number of differences. Your self talk should involve these types of facts, all the time. Gradually you will be able to come out of this.