Yes, I do have some advice: I’d say that it’s time to schedule an appointment with your pastor, who may choose to put you in touch with a spiritual director.
In my view, we all too often give everyone the same discernment advice that we give young men considering Holy Orders. The difference is that other vocations or vows do not ascribe a particular character to the soul as Holy Orders do, and so many young people thus engage in a lot of unnecessary, often neurotic, introspection in vain. Scripture and doctrine make it clear that marriage is our natural vocation, how we are best to live in society on earth. Likewise, religion or consecration is our supernatural vocation, a foretaste of how we shall live in the presence of God in heaven. Too often, we look for some type of sign without considering that we have the responsibility of assessing our available options, temperament, education, family background, and so forth, and making a choice.
When we consider that we must make a choice, or have made a choice, then we must be on guard for the “noonday devil,” that which tries to convince us some time after having made our choice that we chose wrongly. Consider that many other married people are thinking much the same way as you, and that certainly there is a sister somewhere in the world, perhaps one not personally dissimilar from you, who is questioning whether she truly should have taken her vows. We all, indeed, must live with the consequences of our choices.
Experience shows me that when people start thinking the way you are, it indicates not so much a discontent with their state of life, but with other circumstances of their lives. We cannot undo what has been done, but we can add onto it. Think, TTF, do you see your life now (not just your marriage, but your career, your friends, your social life, etc.) as harmonious with your dominant interests, your capacities, your future prospects? Go through and indicate where it is not, and then prayerfully amend it. The only thing worse than seeing your life as a failure is casting blame for that somewhere instead of moving to fix it. “Vocation” is not a once-and-for-all thing that becomes fixed in our youth; it’s a lifelong endavour and process, encompassing not just the state-of-life vocations we tend to think about, but unique personal and professional vocations and so forth.
I suggest a talk with your pastor in large part because a person’s piety is so instrumental to navigating these sometimes treacherous shoals. It allows us, at least now and again, to rise into the heights of self-sacrifice and divine love necessary to continue fulfilling our duties in this world while seeking out the other opportunities that will allow us to cooperate with God and to fulfill those other duties He may have for us if we are fitted and willing to take them. A pastor at least, we should hope, is able to understand the state of your soul and to aid it in diagnosing its vexations. Perhaps you may benefit from other contacts in the Church or the community that you may not even know existed, such as third orders or confraternities. You’ll never know unless you inquire.