Gary Chapman: "Your relationships will never reach their potential until you learn to apologize."
Source: Gary Chapman, Jennifer Thomas. The Five Languages of Apology: How to Experience Healing in All Your Relationships. Northfield Publishing. 2006. pg. 125.
Hopefully, you want to apologize to your spouse because you want to help ease and eventually end the hurt and pain you caused, because you love your spouse, and because you want to do what you can to insure that your marriage is on solid ground.
Your spouse doesn't need perfection from you. What is needed is being sincere and genuine and keeping your promises.